Practice Questions for Business Statistics

Warning: This web page document is quite long and has many (intra)connecting links. Do NOT click on any links until the entire document has been loaded by your web browser.

Return to Brian Schott @ GSU

Return to the list of chapters

Chapter: Hypothesis Testing

Contents:

124-2 Identify the critical value

158-1 use a _____ confidence interval for MU and hence

209-1 so that eight-ounce cups will overflow only 1% of the time

210-1 A company manufactures rope.

720-3 A type I error is always made when:

722-1 The level of significance is (check all that apply):

745-2 Level of confidence is another name for level of significance.

1280-1 What is the calculated value

1285-1 we would reject H(0) if:

1287-2 You will reject H(0) if:

1288-1 The level of significance of this test is approximately:

1290-1 one should _____ the H(0) since the value _____ lies _____

1291-1 "ALPHA = _____, one should _____ the H(0) since the value "

1298-1 A result was said to be statistically significant at the 5% level.

1298-2 The reasoning in rejecting a null hypothesis is __________.

1299-2 The critical value of a test statistic is determined from:

1301-1 significance level of the test is:

1301-2 Which of the following assumptions are needed to

1302-1 "In testing a hypothesis using a statistic Y, a critical region is"

1306-2 Find all values of Z = [XBAR - MU(0)]/[S/SQRT(n)]

1307-1 Which of the following statements do you KNOW is correct?

1308-1 What type of decision is reached when the calculated value of any

1309-1 "ended with a decision of ""reject H(O)""."

1309-2 what is the function of a critical value that is

1312-1 Whether or not causation may be inferred in a research study

1313-3 Your correct interpretation of the outcome is

1323-1 Test the null hypothesis that the new ball

1325-1 Test the appropriate hypothesis at the 5% level.

1336-4 What objection is there to using the rejection region:

1349-3 "If we would reject a null hypothesis at the 5% level, we would also"

1352-1 The decision to use a one-sided or two-sided test is usually made

1352-3 Significance at the ALPHA = .001 level means that the null

1354-2 Testing at a 5% level of significance means that you only have

1489-1 can we conclude that the experimental mean differs

1490-1 Determine a 0.90 confidence interval for the mean reaction time

1493-1 Construct a 95% confidence interval for MU.

1494-1 Do you think that it would be quite unreasonable for

1502-2 Set up a decision rule for H(0): MU => 25

1508-1 "In a sample of 25 physicians, the mean annual income of $47,000"

1567-2 Which of the following assumptions are needed to test

1602-2 "XBAR = 22, one should conclude that:"

1603-1 "If the P-value for your test statistic satisfies P > .25, then:"

1608-1 weight reduction program. After four months the statistics

1609-1 "The meaning of ""testing the hypothesis MU <= 6 versus MU > 6"

1610-3 "Statistical Significance means that, if an experiment were "

1617-1 H(0): MU >= 114 against H(1): MU < 114

1618-1 H(0): MU = 43 against H(1): MU =/= 43

1619-1 "With a computed t-statistic of 2.63, what conclusion should"

1627-1 A new diet for the reduction of cholesterol is introduced.

1628-2 This term she believes that her students are doing sig

1631-1 Past production units of a certain jet engine model showed the mean

1632-1 "Forty-nine American soldiers, observed at random, yield a mean weight"

1635-1 A standard intelligence examination has been given for several years

1646-1 she has collected the final grades of her classes and found

1654-1 "If a statistic is significant at the 5 percent level, then it must be"

1654-2 One can never prove the truth of a statistical (null) hypothesis. One can

1655-1 "If the population mean is known, it makes no sense to test"

1655-2 Since the P-value in a test of hypothesis is based on the specific

1655-3 The descriptive level of significance (P-value) is chosen by

1657-1 A hypothesis accepted at the ALPHA = .20 level of significance

1657-2 A small significance level indicates that the hypothesis

1657-3 If the results of an investigation show that one sleeping tablet

1661-4 "In hypothesis testing, a type I error is"

1662-1 "With which of the following terms is the ""level of significance"" most"

1662-2 better than the old one. The Type I Error is to conclude that:

1664-2 "Usually, one would like the critical region for a test to be _______"

1664-4 "If the number of observations (n) is increased to 2n,"

1665-1 if the population variance (SIGMA**2) is decreased to

1667-2 "If Z(critical) = 2.04, what is the p-value for your test?"

1668-2 For testing the hypothesis MU = 28 against

1669-1 Interpret the quality control procedure described above as a test of

1670-1 What would be the consequences of a Type I and Type II error?

1672-2 When an experimenter selects a particular level of risk (ALPHA) he

1677-1 What type of error might you have made in part a?

1686-3 A Type I error is committed when one accepts the null hypothesis

1688-1 The significance level is computed under the assumption that

1688-2 The risk of type II error does not depend upon the risk of type I

1691-2 "Other things being equal, a small level of significance is desirable."

1693-1 Level of confidence equals (1 - level of significance).

1694-1 "Although we speak of two types of error, in testing any"

1694-2 "Generally, a larger sample size implies a smaller level of"

1702-1 "In this situation, a type II error would be:"

1704-1 Type II error refers to:

1706-2 What is the probability of a Type II error when ALPHA = .05?

2137-1 rejected at the .05 level but not at the .025 level?

2139-1 The value(s) of the test statistic you would use is (are):

2140-1 Sixteen one-acre plots of wheat were harvested.

2143-1 we find a critical value of t equals 2.015. This means that

2143-2 "According to these data, the researcher can reject his H(0) with"

2147-1 "For each of the following sets of information, find and specify"

2151-2 have a higher average height than American males as a whole?

2789-1 the starting point of the region of rejection in terms of XBAR

2790-1 Should the teacher use the new method? Why?

2792-1 What is the smallest ALPHA-level that could be chosen before you

2796-1 The Crapi Cable Company #35 cable has a mean breaking strength of 1800

2799-1 Analyze the data at both levels after setting up appropriate

2800-1 at a .001 significance level. For a sample of 49

2803-1 "Since the observed Z-value is _______ than the table value, we would

2808-1 Test the company's claim using ALPHA = .01.

2811-2 What is the significance probability of the observed result?

Return to the list of chapters

Return to Brian Schott @ GSU

Questions:

124-2

    Q:  It is desired to test the claim  that  a  steady  diet  of wolfbane will
        cause a lycanthrope (werewolf) to lose 10 lbs. over 5 months.   A random
        sample of 49 lycanthropes was taken yielding an average weight loss over
        5 months of 12.5 pounds, with S  =  7 lbs.   Identify the critical value
        suitable for  conducting  a  two-tail  test  of  the  hypothesis at  the
        2% level.

        a.  2.06
        b.  2.58
        c.  1.96
        d.  1.65
        e.  2.33

Back to this chapter's Contents

Look at the answer


158-1

    Q:  Molybdenum  rods produced on a production line are supposed to average
        2.2 inches in length.  It is desired to check whether the process is in
        control.  Let X = length of such a rod.  Assume X is approximately nor-
        mally distributed with mean = MU and variance = SIGMA**2, where the mean
        and the variance are unknown.

        Suppose a sample of n = 400 rods  is  taken  and yields a sample average
        length of XBAR = 2 inches, and SUM((X - XBAR)**2) = 399.

        To test H(0):  MU = 2.2 vs. H(1):  MU =/= 2.2 at level ALPHA = 8%, one
        would use a _____ confidence interval for MU and hence a table value
        of _____.

        a)  92%, 1.67
        b)  92%, 1.41
        c)  92%, 1.75
        d)  96%, 2.06
        e)  96%, 1.75

Back to this chapter's Contents

Look at the answer


209-1

    Q:  A soft drink machine can be regulated so that it discharges an average
        of MU ounces per cup.  If the ounces of fill are normally distributed
        with standard deviation equal to .3 ounces, give the setting for MU
        so that eight-ounce cups will overflow only 1% of the time.

Back to this chapter's Contents

Look at the answer


210-1

    Q:  A company manufactures rope.  From a large number of tests over a long
        period of time, they have found a mean breaking strength of 300 lbs.
        and a standard deviation of 24 lbs.  Assume that these values are
        MU and SIGMA.

        It is believed that by a newly developed process, the mean breaking
        strength can be increased.

        (a)  Design a decision rule for rejecting the old process with an
             ALPHA error of 0.01 if it is agreed to test 64 ropes.

        (b)  Under the decision rule adopted in (a), what is the probability
             of accepting the old process when in fact the new process has
             increased the mean breaking strength to 310 lbs.?  Assume SIGMA
             is still 24 lbs.  Use a diagram to illustrate what you have done,
             i.e., draw the reference distributions.

Back to this chapter's Contents

Look at the answer


720-3

    Q:  A type I error is always made when:
        a.  the null hypothesis is rejected when it is true
        b.  the null hypothesis is not rejected when it is false
        c.  the research hypothesis is rejected when it is true
        d.  the research hypothesis is not rejected when it is false

Back to this chapter's Contents

Look at the answer


722-1

    Q:  The level of significance is (check all that apply):

        A.  the probability of rejecting the null hypothesis when the null
            hypothesis is true.
        B.  the magnitude of the sample size.
        C.  symbolized by the greek letter ALPHA.
        D.  none of the above.

Back to this chapter's Contents

Look at the answer


745-2

    Q:  True or False?  If False, correct it.

        Level of confidence is another name for level of significance.

Back to this chapter's Contents

Look at the answer


1280-1

    Q:  It is desired to test the claim that a steady diet of wolfbane
        will cause an 18-year-old lycanthrope werewolf to lose EXACTLY
        10 lbs. over 5 months.  A random sample of 49 lycanthropes was
        taken, yielding an average weight loss over 5 months of 12.5 lbs.
        with S = 7 lbs.  Let ALPHA = .02.  What is the calculated value
        suitable for testing the above hypothesis?

        a.  12.5
        b.  7 * 2.5
        c.  2.5
        d.  -2.5
        e.  .35

Back to this chapter's Contents

Look at the answer


1285-1

    Q:  A sample of size 36 is taken from a population with unknown mean
        MU and standard deviation SIGMA = 3.

        In a test of H(0):  MU = 5 versus H(1):  MU =/= 5 at ALPHA = .01,
        we would reject H(0) if:

        (a)  XBAR - 5 > 1.29 or 5 - XBAR > 1.29

        (b)  XBAR - 5 > 7.74 or 5 - XBAR > 7.74

        (c)  XBAR - 5 > 1.29 or 5 - XBAR < 7.74

        (d)  XBAR - 5 < 1.29 or 5 - XBAR < 1.29

        (e)  XBAR - 5 < 7.74 or 5 - XBAR < 7.74

Back to this chapter's Contents

Look at the answer


1287-2

    Q:  The standard deviation of a large population is 20.  To test:

            H(0):  MU = 4   vs.   H(A):  MU > 4

        at level of significance .05, a sample of size 100 will be taken.
        You will reject H(0) if:

        (a)  XBAR >= 7.3                      (d)  XBAR >= 7.8 or XBAR <= .2
        (b)  XBAR >= 7.3 or XBAR <= .8        (e)  none of the above
        (c)  XBAR >= 7.8

Back to this chapter's Contents

Look at the answer


1288-1

    Q:  To test H(0): MU = 20 vs. H(A): MU =/= 20, a sample of 400 will be
        taken from a large population, whose standard deviation is 5.  H(0) will
        be rejected if XBAR >= 20.5 or XBAR <= 19.5.  The level of significance
        of this test is approximately:

        a.  .05
        b.  .02
        c.  .10
        d.  .20
        e.  .15

Back to this chapter's Contents

Look at the answer


1290-1

    Q:  Molybdenum rods are produced by a production line setup.   It is desir-
        able to check whether the process is in control.  Let X = length of such
        a rod.  Assume X is approximately  normally  distributed  with mean = MU
        and variance = SIGMA**2, where the mean and variance are unknown.

        Take n = 400 sample rods, with sample average length XBAR = 2 inches,
        and SUM((X - XBAR)**2) = 399.

        In testing H(0):  MU = 2.2 vs. H(1):  MU =/= 2.2 at level ALPHA = 8%,
        one should _____ the H(0) since the value _____ lies _____ the
        confidence interval.

        a)  not reject, 2.2, within
        b)  reject, 2, outside of
        c)  reject, 2.2, outside of
        d)  not reject, 2, within
        e)  either b or c

Back to this chapter's Contents

Look at the answer


1291-1

    Q:  Molybdenum rods are produced by a production line setup.  It is desired
        to check whether the process is in control.  Let X = length of such a
        rod.  Assume X is approximately normally distributed with mean = MU
        and variance = SIGMA**2, where the mean and variance are unknown.

        Take n = 400 sample rods, with sample average length XBAR = 2 inches
        and SUM((X - XBAR)**2) = 399.

        If one were testing H(0):  MU = 1 vs. H(1):  MU =/= 1 at level
        ALPHA = _____, one should _____ the H(0) since the value 1 lies
        _____ the confidence interval.

        a)  16%, not reject (continue), within
        b)   8%, not reject (continue), within
        c)   4%, not reject (continue), within
        d)   4%, not reject (continue), to the left of
        e)   4%, reject, to the left of

Back to this chapter's Contents

Look at the answer


1298-1

    Q:  A result was said to be statistically significant at the 5% level.
        This means:

             a.  the null hypothesis is probably wrong
             b.  the result would be unexpected if the null hypothesis were
                 true
             c.  the null hypothesis is probably true
             d.  none of the above.

Back to this chapter's Contents

Look at the answer


1298-2

    Q:  The reasoning in rejecting a null hypothesis is __________.

             a.  that a significant result usually occurs when the null hypo-
                 thesis is false.
             b.  that a significant result seldom occurs when the null hypo-
                 thesis is true.
             c.  some reason other than (a) or (b).
             d.  both (a) and (b).

Back to this chapter's Contents

Look at the answer


1299-2

    Q:  The critical value of a test statistic is determined from:

        a.  calculations from the data.

        b.  calculations based on many actual repetitions of the same
            experiment.

        c.  the sampling distribution of the statistic assuming H(A).

        d.  the sampling distribution of the statistic assuming H(O).

Back to this chapter's Contents

Look at the answer


1301-1

    Q:  Suppose  a  t-test  for the hypothesis that H(O): MU = 0 vs. H(A): MU
        =/= 0 is carried out and we  find  t(obs.)  =  1.8.  The  descriptive
        significance level of the test is:

             a.  the Type I error probability of the test.
             b.  the probability of getting a t-value >= 1.8.
             c.  the probability of getting a t-value >= 1.8 or <= -1.8.
             d.  the Type II error probability of the test.
             e.  none of these.

Back to this chapter's Contents

Look at the answer


1301-2

    Q:  Indicate which assumptions are needed to use the sample mean and normal
        tables to test a hypothesis about a population mean, MU, and known
        variance, SIGMA**2.  Which of the following assumptions are needed to
        use XBAR, the mean of the data, and normal tables to test a hypothesis
        about MU?

               I.  the data are a random sample
              II.  the population distribution is normal
             III.  the sample size is large

             a.  I, II, and III
             b.  I and either II or III
             c.  II and III
             d.  only II
             e.  none of the above

Back to this chapter's Contents

Look at the answer


1302-1

    Q:  In testing a hypothesis using a statistic Y, a critical region is
        chosen to meet which of the following conditions:

               I.  the probability of Y falling in the critical region
                   when the null hypothesis is true is ALPHA

              II.  the probability of Y falling in the critical region  when
                   the alternative hypothesis is true is greater than it not
                   falling in the critical region.

             III.  the sample size is large

             a.  I, II, and III
             b.  I and II only
             c.  I only
             d.  II only
             e.  none of the above

Back to this chapter's Contents

Look at the answer


1306-2

    Q:  Suppose you are going to test H(O):  MU  =  MU(0)
                                      H(A):  MU =/= MU(0)

        using ALPHA =.05.  Find all values of Z = [XBAR - MU(0)]/[S/SQRT(n)]
        for which H(O) should be rejected.

        a)  Z < -1.96               b)  Z < -1.645 or Z > 1.645
        c)  -1.96 < Z < 1.96        d)  Z < -1.96 or Z > 1.96
        e)  -1.645 < Z < 1.645

Back to this chapter's Contents

Look at the answer


1307-1

    Q:  Suppose a random sample of size 25 is selected from a population with
        mean MU, the value of which is unknown.   The  sample statistics  are
        XBAR = 6.4, s = 10.  Test

            H(O):  MU = 10
            H(A):  MU < 10 using ALPHA = .05.

        Which of the following statements do you KNOW is correct?

        a)  A type 1 error has been committed.
        b)  H(O) is rejected.
        c)  H(O) is not rejected.
        d)  Statements (a) and (b) are correct.
        e)  None of the above.

Back to this chapter's Contents

Look at the answer


1308-1

    Q:  What type of decision is reached when the calculated value of any test
        statistic falls in the critical region when a false null hypothesis is
        being tested?

        a)  A correct decision.
        b)  Type I error.
        c)  Type II error.
        d)  The type of decision can not be determined from the information
            given.
        e)  None of the above are correct.

Back to this chapter's Contents

Look at the answer


1309-1

    Q:  A home owner claims that the current market value of his house is at
        least $40,000.  Sixty real estate agents were asked independently to
        estimate the house's value.  The hypothesis test that followed ended
        with a decision of "reject H(O)".  Which of the following statements
        accurately states the conclusion?

        a)  The home owner is right, the house is worth $40,000.
        b)  The home owner is right, the house is worth less than $40,000.
        c)  The home owner is wrong, the house is worth less than $40,000.
        d)  The home owner is wrong, the house is worth more than $40,000.
        e)  The home owner is wrong, he should not sell his home.

Back to this chapter's Contents

Look at the answer


1309-2

    Q:  In hypothesis testing, what is the function of a critical value that is
        taken from the tables?

        a.  It is equal to the calculated statistic from the observed data.
        b.  It is the point where the decision changes from reject to fail to
            reject.
        c.  It is the center of the distribution of X's.
        d.  It is a point which is 1 standard deviation away from the mean.

Back to this chapter's Contents

Look at the answer


1312-1

    Q:  Whether or not causation may be inferred in a research study
            (a)  is indicated by the magnitude of the test statistic employed.
            (b)  is given by the final p-value.
            (c)  must be decided by the investigator.
            (d)  depends upon the sample size employed in the study.

Back to this chapter's Contents

Look at the answer


1313-3

    Q:  You have drawn a random sample of size n from a specified population and
        you test the hypothesis that MU = 50.  Suppose that you are unable to
        reject the hypothesis.  Your correct interpretation of the outcome is
        that
        a.  in the population, MU = 50.
        b.  probability is high that in the population, MU = 50.
        c.  the sample data are not inconsistent with the hypothesis that in
            the population, MU = 50.
        d.  all of the above are acceptable interpretations.

Back to this chapter's Contents

Look at the answer


1323-1

    Q:  The FMA Company has designed a new type of 16 lb. bowling ball.   The
        company  knows  that  the  average man who bowls in  a scratch league
        with the company's old ball  has  a  bowling  average  of  155.   The
        variance  of these averages is 100.  The company asks a random sample
        of 100 men bowling in scratch leagues to bowl  for  five  weeks  with
        their  new  ball. The mean of bowling averages for these men with the
        new ball is 170. There is no reason to believe the  variance  is  any
        different  with  the new ball.  Test the null hypothesis that the new
        ball does  not  improve  a  bowler's  average  at  the  5%  level  of
        significance.

Back to this chapter's Contents

Look at the answer


1325-1

    Q:  A reading coordinator in a large public school system suspects that
        poor readers may test lower in IQ than children whose reading is satis-
        factory.  He draws a random sample of 30 fifth grade students who are
        poor readers.  Historically fifth grade students in the school system
        have had an average IQ of 105.  The sample of 30 has XBAR = 101.5 and
        S(XBAR) = 1.42.  Test the appropriate hypothesis at the 5% level.

Back to this chapter's Contents

Look at the answer


1336-4

    Q:  What objection is there to using the rejection region:

        [68 - [.125*(SIGMA/SQRT(N))]] < XBAR < [68 + [.125*(SIGMA/SQRT(N))]]

        in testing the hypothesis H(O):  MU = 68?  HINT:  What would be the
        level of significance for this test?

Back to this chapter's Contents

Look at the answer


1349-3

    Q:  True or False?  If False, correct it.

        If we would reject a null hypothesis at the 5% level, we would also
        reject it at the 1% level.

Back to this chapter's Contents

Look at the answer


1352-1

    Q:  True or False?  If False, correct it.

        The decision to use a one-sided or two-sided test is usually made
        after the data is analyzed.

Back to this chapter's Contents

Look at the answer


1352-3

    Q:  True or false? If false, explain why.

             Significance at the ALPHA = .001 level means that the null hypo-
             thesis is almost certainly false.

Back to this chapter's Contents

Look at the answer


1354-2

    Q:  True or false? If false, explain why.

             Testing at a 5% level of significance means that you only have a
             5% chance of rejecting the null hypothesis.

Back to this chapter's Contents

Look at the answer


1489-1

    Q:  The  calculated nitrogen content  of  pure  benzanilide is 7.10%.  Five
        repeat  analyses  of "representative"  samples  yielded values of 7.11%,
        7.08%, 7.06%, 7.06%, and 7.04%.  Using an ALPHA level of size 5%, can we
        conclude that the experimental  mean  differs from  the expected  value?
        Assume that the measured values are approximately normally distributed.

Back to this chapter's Contents

Look at the answer


1490-1

    Q:  The following are the reaction times in seconds of five people to a
        particular stimulus:  7,8,6,10,9
        XBAR = 40/5 = 8
            S(X)**2 = [(-1)**2 + (0)**2 + (-2)**2 + (1)**2]/4
                    = 10/4
                    = 2.5
            
        a.  Do these data present sufficient indication that the mean reac-
            tion time of all people would be less than ten seconds?  Test at
            the 0.05 level of significance (ALPHA = .05).

        b.  Determine a 0.90 confidence interval for the mean reaction time
            for all people to this stimulus.

        c.  State any assumptions that must be made in order to do parts (a)
            and/or (b).

Back to this chapter's Contents

Look at the answer


1493-1

    Q:  Suppose in a sample of 25 people, the mean height XBAR was observed
        to be 70 inches.  Suppose also SIGMA = 3.

        A. Construct a 95% confidence interval for MU.

        B. Would you reject the hypothesis H(0):MU = 71
           versus H(1):MU =/= 71 on the basis of the observations,
           when testing at level ALPHA = .05?

        C. Would you reject the hypothesis H(0):MU = 72
           versus the alternative H(1):MU =/= 72 on the basis of the
           observations, when testing at level ALPHA = .05?

        D. Would you reject the hypothesis H(0):MU = 69 versus
           the (one-sided) alternative H(1):MU > 69 on the basis of your
           observations, when testing at level ALPHA = .05?

Back to this chapter's Contents

Look at the answer


1494-1

    Q:  A floor manager of a large department store is studying the buying
        habits of the store's customers.  Suppose he assumes that monthly
        income of these customers is normally distributed with a standard
        deviation of 500.  If he draws a random sample of size N = 100 and
        obtains a sample mean of YBAR = 800,

        A 0.95 confidence interval for the true population mean is 
        702 < MU < 898.
        Do you think that it would be quite unreasonable for
            the true population mean to be $600?  Explain.

Back to this chapter's Contents

Look at the answer


1502-2

    Q:  Suppose that you are concerned with the claim that MU > 25.  Assume that
        you know that SIGMA = 1.  Set up a decision rule for H(0): MU => 25 for
        a sample of size 10 such that the type 1 error rate is 2%.

Back to this chapter's Contents

Look at the answer


1508-1

    Q:  In a sample of 25 physicians, the mean annual income of $47,000 with a
        variance of $360,000.

        a.  Estimate with 95% confidence the mean income for all physicians.
        b.  What assumptions are necessary to make this a valid estimate?  Do
            you feel the assumptions are reasonable in this case?  Why or why
            not?
        c.  Based on your answer in (a), would the null hypothesis that the true
            mean is $50,000 be continued or rejected at the 5% significance
            level?  Why?

Back to this chapter's Contents

Look at the answer


1567-2

    Q:  Which of the following assumptions are needed to test a hypothesis
        about mean MU in a population with known variance SIGMA**2 using
        the mean of the data X(1) ... X(N) and normal tables:

              I.  The data are a random sample.
             II.  The population distribution is normal.
            III.  The sample size is large.

        a.  I, II and III                d.  only II
        b.  I and either II or III       e.  none of these
        c.  II and III

Back to this chapter's Contents

Look at the answer


1602-2

    Q:  In testing H(0):  MU <= 20 vs. H(A):  MU > 20 when ALPHA = .05,
        n = 25, S**2 = 16 and XBAR = 22, one should conclude that:

        a.  MU > 20 with 5% chance of error
        b.  MU > 20 with 5 % confidence
        c.  MU = 20 with 95% confidence
        d.  MU = 20 with 95% chance of error

Back to this chapter's Contents

Look at the answer


1603-1

    Q:  If the P-value for your test statistic satisfies P > .25, then:

        (a)  you would not reject H(O)
        (b)  you would reject H(O) for ALPHA = .05
        (c)  you would reject H(O) for ALPHA = .10
        (d)  your acceptance region has a lower limit of .25
        (e)  none of these

Back to this chapter's Contents

Look at the answer


1608-1

    Q:  Nine men with a genetic condition that causes obesity entered a
        weight reduction program.  After four months the statistics of
        weight loss were:  XBAR = 11.2, S = 9.0.  The researcher wants
        to test the hypothesis:  The average four-month weight loss in
        such a program is <= 6 pounds verses the alternative: > 6 pounds
        at a 5% significance level.  Given the data of our problem, we

        a.  reject the hypothesis.
        b.  reserve judgement about the hypothesis.

Back to this chapter's Contents

Look at the answer


1609-1

    Q:  The meaning of "testing the hypothesis MU <= 6 versus MU > 6
        at a 5% significance level" is:

        a.  if the population mean MU is > 6, the probability of deciding
            wrongly is at least 95%.

        b.  if the population mean MU is <= 6, the probability of deciding
            wrongly is at most 5%.

        c.  if the population mean MU is > 6, the probability of deciding
            wrongly is at most 5%.

        d.  no matter what the population mean is, the probability of
            deciding wrongly is at most 5%.

Back to this chapter's Contents

Look at the answer


1610-3

    Q:  Statistical Significance means that, if an experiment were replicated
        over and over again:

        a)  the same results would occur again with certainty
        b)  the same results would probably occur
        c)  the same results would probably not occur
        d)  the same results would certainly not occur again.

Back to this chapter's Contents

Look at the answer


1617-1

    Q:  Suppose X(1) ... X(10) is a sample from a normal population with
        mean = MU and variance = 22.5.  The critical region for testing
        H(0):  MU >= 114 against H(1):  MU < 114 at significance level
        .05 is:

        Reject H(0) if
        a.  XBAR < 112.00
        b.  XBAR < 111.54
        c.  XBAR < 111.25
        d.  XBAR < 111.06
        e.  none of these

Back to this chapter's Contents

Look at the answer


1618-1

    Q:  If X(1),...,X(10) is a sample from a normal population with mean = MU
        and variance = SIGMA**2, with SIGMA**2 unknown, and the sample standard
        deviation (biased estimator) s = 7.5, then the critical region for
        testing H(0):  MU = 43 against H(1):  MU =/= 43 at ALPHA = .01 is:

        Reject H(0) if
        a.  XBAR > 50.02 or XBAR < 35.98
        b.  XBAR > 51.12 or XBAR < 34.88
        c.  XBAR > 50.56 or XBAR < 35.44
        d.  XBAR > 50.72 or XBAR < 35.28
        e.  none of these.

Back to this chapter's Contents

Look at the answer


1619-1

    Q:  Blood samples from 40  patients  are  analyzed  for  glucose  by  two
        different   methods.  With  a  computed  t-statistic  of  2.63,  what
        conclusion should you draw?

             a.  There is a significant difference in methods, p < .005.
             b.  There is a significant difference in methods, p < .01.
             c.  There is a significant difference in methods, p < .05.
             d.  There is no significant difference in the two methods.

Back to this chapter's Contents

Look at the answer


1627-1

    Q:  A new diet for the reduction of cholesterol is introduced.  In order to
        test this procedure, nine patients on this new diet had observed choles-
        terol levels of:

             patient        cholesterol        patient        cholesterol

                1               240               6               220
                2               290               7               190
                3               220               8               230
                4               250               9               200
                5               260

        XBAR = 210    S**2 = SUM(([X(i) - 210]**2)/8) = 950    S = 30.9

        Assume cholesterol levels are normally distributed.

        This new method of cholesterol reduction was used on a sample from a
        population with a mean MU cholesterol level of 225.  Test the hypo-
        thesis that the procedure used was effective (ALPHA = .05).

        a.  H(O): _______________.

        b.  H(A): _______________.

        c.  test statistic = _______________.

        d.  critical region = _______________.

        e.  Does the test statistic (c) fall in the critical region (d)?

        f.  Conclusion?

Back to this chapter's Contents

Look at the answer


1628-2

    Q:  A teacher has been conducting the same course for many years.   As  part
        of her check on her own teaching and on the general effectiveness of the
        students in her classes from year to year, she has been giving  the same
        pop quiz during the 4th week of classes.  Over the years  the score  has
        averaged 13.5.  This term she believes that her students are doing  sig-
        nificantly different than usual.  If she can  establish  support  of her
        perception she will alter her teaching methods  for this class.   On the
        basis of the test scores below should she conclude that there is support
        for her perception and change her methods?  On what  basis do  you offer
        your consultation to her?

        Scores:  20, 19, 6, 4, 3, 10, 13, 14, 16, 17,
                 10, 11, 8, 9, 11, 20, 18, 6, 4, 13.
        XBAR = 11.6
        S = 5.49

Back to this chapter's Contents

Look at the answer


1631-1

    Q:  Past production units of a certain jet engine model showed the mean
        military thrust to be 7600 pounds.  The first ten production units
        manufactured after a model change yielded military thrusts of 7620,
        7680, 7570, 7700, 7650, 7720, 7600, 7540, 7670, and 7630.  Is there
        sufficient evidence (use ALPHA = 0.05) that the model change
        resulted in a higher average military thrust?
        Finding: YBAR = 7638
        S(Y) = SQRT((583,420,000 - ((76,380)**2/10))/9) = 57.3 

Back to this chapter's Contents

Look at the answer


1632-1

    Q:  Forty-nine American soldiers, observed at random, yield a mean weight
        of 160 pounds with a standard deviation (s) of 11 pounds.  Are these
        observations consistent  with  the assumption that the mean weight of
        all American soldiers is 170 pounds?

Back to this chapter's Contents

Look at the answer


1635-1

    Q:  A standard intelligence examination has been given for several  years
        with  an  average  score  of 80 and a standard deviation of 7.  If 25
        students taught with special emphasis on reading skill, obtain a mean
        grade  of  83 on the examination, is there reason to believe that the
        special emphasis changes the result on the test?   Use ALPHA = .05.

Back to this chapter's Contents

Look at the answer


1646-1

    Q:  A teacher has just taken a course in statistics and decides to
        put her new knowledge to work.  During the last ten years she
        has collected the final grades of her classes and found the mean
        to be 73.6 with a standard deviation = 9.  The final grades for
        this years class are:  95, 97, 84, 64, 72, 88, 92, 61, 76, 74,
        84, 85, 89, 75, 76, 64, 61, 72, 63, 74.
        The teacher wishes to know if she should consider this years
        class as significantly different than previous years.  The
        teacher did very well in her statistics class.  What would you
        believe her decision was?  Why?
        XBAR = 77.3; Hint: Do NOT calculate S in this problem.

Back to this chapter's Contents

Look at the answer


1654-1

    Q:  True or False?  If False, correct it.

        If a statistic is significant at the 5 percent level, then it must be
        significant at the 1 percent level also.

Back to this chapter's Contents

Look at the answer


1654-2

    Q:  True or False?  If False, correct it.

        One can never prove the truth of a statistical (null) hypothesis.  One can
        only tend to discount it.

Back to this chapter's Contents

Look at the answer


1655-1

    Q:  True or False?  If False, correct it.

        If the population mean is known, it makes no sense to test hypotheses
        concerning the population mean.

Back to this chapter's Contents

Look at the answer


1655-2

    Q:  True or False?  If False, correct it.

        Since the P-value in a test of hypothesis is based  on  the  specific
        observed value of a test statistic, it cannot be used in a two-sided
        test.

Back to this chapter's Contents

Look at the answer


1655-3

    Q:  True or False?  If False, correct it.

        The descriptive level of significance  (P-value)  is  chosen  by  the
        investigator before his experiment is conducted.

Back to this chapter's Contents

Look at the answer


1657-1

    Q:  True or False?  If False, correct it.

        A hypothesis accepted at the ALPHA = .20 level of significance
        is probably true.

Back to this chapter's Contents

Look at the answer


1657-2

    Q:  True or False?  If False, correct it.

        A small significance level indicates that the hypothesis will
        probably be continued.

Back to this chapter's Contents

Look at the answer


1657-3

    Q:  TRUE OR FALSE. IF FALSE EXPLAIN WHY.

            If the results of an investigation show that one sleeping tablet
        works better than another at the 5% level of significance, the
        conclusion would be similar if tested at the 10% level of significance.

Back to this chapter's Contents

Look at the answer


1661-4

    Q:  In hypothesis testing, a type I error is

        a.  failing to reject the null hypothesis when it is false.
        b.  failing to reject the null hypothesis when it is true.
        c.  rejecting the null hypothesis when it is true.
        d.  rejecting the null hypothesis when it is false.

Back to this chapter's Contents

Look at the answer


1662-1

    Q:  With which of the following terms is the "level of significance" most
        closely associated?
            a.  one-tailed test of significance
            b.  two-tailed test of significance
            c.  type 1 error
            d.  type 2 error

Back to this chapter's Contents

Look at the answer


1662-2

    Q:  Given the null hypothesis:  that a new process is as good as or
        better than the old one.  The Type I Error is to conclude that:

        (a)  the old process is as good or better when it is not             
        (b)  the old process is better when it is
        (c)  the old process is better when it is not
        (d)  the new process is as good or better when it is             

Back to this chapter's Contents

Look at the answer


1664-2

    Q:  Usually, one would like the critical region for a test to be _______
        (long or short).  The "size" of the critical region is determined by
        _______ (ALPHA or BETA).

Back to this chapter's Contents

Look at the answer


1664-4

    Q:  If the number of observations (n) is increased to 2n, the level of
        significance (ALPHA) is:

        a.  increased     b.  unaffected     c.  decreased

Back to this chapter's Contents

Look at the answer


1665-1

    Q:  When conducting a test for the population mean, if the population vari-
        ance (SIGMA**2) is decreased to [(SIGMA**2)/2], then the level of sig-
        nificance (ALPHA) is:

        a.  increased     b.  unaffected     c.  decreased

Back to this chapter's Contents

Look at the answer


1667-2

    Q:  Suppose you are testing H(O): MU <= 21 vs. H(A):  MU > 21, from a normal
        distribution with SIGMA**2 known equal to 28 and n = 13.  If Z(critical)
        = 2.04, what is the p-value for your test?

             a.  .0207             d.  .025
             b.  .4793             e.  none of these
             c.  .0414

Back to this chapter's Contents

Look at the answer


1668-2

    Q:  A population is known to have a variance of 16. When a sample of size
        25  is  taken,  the  sample  variance  is  found to be 14, while the
        sample mean is 30. For testing the hypothesis MU =  28  against  the
        alternative MU =/= 28 at the 0.10 level, the critical values are:

             a.  +/- 1.711
             b.  +/- 1.318
             c.  +/- 1.645
             d.  +/- 1.28
             e.  none of these

Back to this chapter's Contents

Look at the answer


1669-1

    Q:  Past experience shows that, if a certain machine is adjusted properly, 5
        percent of the items turned out by the machine are defective.  Each day
        the first 25 items produced by the machine are inspected for defects.
        If three or fewer defects are found, production is continued without
        interruption.  If four or more items are found to be defective, produc-
        tion is interrupted and an engineer is asked to adjust the machine.
        After adjustments have been made, production is resumed.  This proce-
        dure can be viewed as a test of the hypothesis p = .05 against the
        alternative p > .05, p being the probability that the machine turns
        out a defective item.  In test terminology, the engineer is asked to
        make adjustments only when the hypothesis is rejected.

        Interpret the quality control procedure described above as a test of
        the indicated hypothesis.  A Type I error results in:

        a.  a justified production stoppage to carry out machine adjustments.
        b.  an unnecessary interruption of production.
        c.  the continued production of an excess of defective items.
        d.  the continued production, without interruption, of items that
            satisfy the accepted standard.

Back to this chapter's Contents

Look at the answer


1670-1

    Q:  In assessing the weather prior to leaving our residences on a spring
        morning, we make an informal test of hypothesis "The weather will be
        fair today."  Using the "best" information available to us, we complete
        the test and dress accordingly.  What would be the consequences  of  a
        Type I and Type II error?

        (1)  Type I error:  inconvenience in carrying needless rain equipment;
             Type II error: clothes get soaked.
        (2)  Type I error:  clothes get soaked; Type II error:  inconvenience
             in carrying needless rain equipment.
        (3)  Type I error:  clothes get soaked; Type II error:  no consequence
             since Type II error cannot be made.
        (4)  Type I error:  no consequence since a Type I error cannot be made;
             Type II error: inconvenience in carrying needless rain equipment.

Back to this chapter's Contents

Look at the answer


1672-2

    Q:  When an experimenter selects a particular level of risk (ALPHA) he
        effectively is setting the probability of rejecting H(0) when in fact
        it is true.
        a.  true
        b.  false

Back to this chapter's Contents

Look at the answer


1677-1

    Q:  The mean weight of adult women in the U.S. is 140 lb. with a standard
        deviation of 20 lb.  You are willing to accept the report of the
        standard deviation but not the mean.  You selected 400 women at random
        and measured their weight and found the average in this group to be
        137 lb.

        a.  Test at ALPHA=.05 the hypothesis that the true weight is 140 lb.
        b.  What type of error might you have made in part a?  Do you know the
            probability of making such an error?  If so, what is it?  If not,
            why not?

Back to this chapter's Contents

Look at the answer


1686-3

    Q:  True or False?  If False, explain why.

        A Type I error is committed when one accepts the null hypothesis
        when it is false.

Back to this chapter's Contents

Look at the answer


1688-1

    Q:  True or False?  If False, correct it.

        The significance level is computed under the assumption that the
        alternative hypothesis is true.

Back to this chapter's Contents

Look at the answer


1688-2

    Q:  True or False?  If False, correct it.

        The risk of type II error does not depend upon the risk of type I
        error.

Back to this chapter's Contents

Look at the answer


1691-2

    Q:  True or False?  If False, correct it.

        Other things being equal, a small level of significance is desirable.

Back to this chapter's Contents

Look at the answer


1693-1

    Q:  True or False?  If False, correct it.

        Level of confidence equals (1 - level of significance).

Back to this chapter's Contents

Look at the answer


1694-1

    Q:  True or False?  Explain your answer.

        Although we speak of two types of error, in testing any
        specified hypothesis we can make only one.

Back to this chapter's Contents

Look at the answer


1694-2

    Q:  True or False?  If False, correct it.

        Generally, a larger sample size implies a smaller level of
        significance.

Back to this chapter's Contents

Look at the answer


1702-1

    Q:  Given the null hypothesis: that a process is producing no  more  than
        the maximum allowable rate of defective items.   In this situation, a
        type II error would be:

        (a)  to conclude that the process is producing too many defectives
             when it actually is not

        (b)  to conclude that the process is not producing too many defec-
             tives when it actually is

        (c)  to conclude that the process is not producing too many defec-
             tives when it is not

        (d)  to conlcude that the process is producing too many defectives
             when it is.

Back to this chapter's Contents

Look at the answer


1704-1

    Q:  Type II error refers to:

        a.  rejecting the null hypothesis when the alternative is true.

        b.  choosing the wrong decision rule.

        c.  not rejecting the null hypothesis when the alternative is
            true.

        d.  incorrectly assuming the data are normally distributed.

        e.  none of these.

Back to this chapter's Contents

Look at the answer


1706-2

    Q:  What is the probability of a Type II error when ALPHA = .05?
            (1)  .025                   (2)  .050
            (3)  .950                   (4)  .975
            (5)  Cannot be determined without more information

Back to this chapter's Contents

Look at the answer


2137-1

    Q:  16 observations are taken from a normal population in order  to  test
        the  null  hypothesis  H(O):  MU  =  10  against  H(A):  MU  < 10.  A
        t-statistic is evaluated.  In which case would H(O)  be  rejected  at
        the .05 level but not at the .025 level?

        a.  t = -2.12
        b.  t = -2.50
        c.  t = 2.12
        d.  t = 10 - 2.50 = 7.50
        e.  t = 10 - 2.12 = 7.88

Back to this chapter's Contents

Look at the answer


2139-1

    Q:  A sample of size 26 is taken from a finite Normal population in which
        the variance is known to be 25.  It is desirable to test the hypothe-
        sis that the mean is greater than 50, with ALPHA = .025.  The critical
        value(s) of the test statistic you would use is (are):

        (a)  -1.96, 1.96          (d)  -1.645
        (b)  1.96                 (e)  -2.060, 2.060
        (c)  1.645                (f)  1.708

Back to this chapter's Contents

Look at the answer


2140-1

    Q:  Sixteen one-acre plots of wheat were harvested.  Their average yield
        was found to be 701 bushels, and their standard deviation was 50 bu.
        Since last year's crop yielded 680 bu./acre, we wish to test H(0):
        MU <= 680 against H(A): MU > 680 at ALPHA = .05.  Based on the above
        data we should

        a.  not reject H(0).             b.  reject H(0).

Back to this chapter's Contents

Look at the answer


2143-1

    Q:  Employing ALPHA = 0.05, one-tailed test, for 5 df, we find that the
        critical value of t equals 2.015.  This means that
            (1)  in this t-distribution, 5% of the area lies below t=-2.015.
            (2)  there is a 95% probability of obtaining a t-ratio less than
                 2.015.
            (3)  if our obtained t = 2.00, we cannot reject H(0) using the
                 .05 level.
            (4)  all of the above.
            (5)  none of the above.

Back to this chapter's Contents

Look at the answer


2143-2

    Q:  The birthweight of babies is normally distribution with a mean of 3.8
        kg.  A researcher suspects that the weight of babies from mothers who
        smoked a lot during pregnancy will be lower than the population mean.
        To examine this, he takes a random sample of 26 babies from mothers who
        smoked a lot.  The mean birthweight in this group was 3.48 kg with a
        standard deviation of .80 kg. (biased estimator of SIGMA**2).  He takes
        as H(0):  MU >= 3.80 kg and as H(1):  MU < 3.80 kg.  According to these
        data, the researcher can reject his H(0) with
        a.  2.5 % probability of a type I error
        b.  5 % probability of a type I error
        c.  10% probability of a type I error
        d.  95% probability of a type I error

Back to this chapter's Contents

Look at the answer


2147-1

    Q:  For each of the following sets of information, find and specify the
        appropriate critical region, test the null hypothesis, and draw a
        conclusion.

        a)  H(0):  MU = 16            n = 27
            H(A):  MU =/= 16          YBAR = 15.0
            ALPHA = .02               s**2 = 3.0

        b)  H(0):  MU <= 18.2         n = 250
            H(A):  MU > 18.2          YBAR = 18.7
            ALPHA = .005              s**2 = 3.6

        c)  H(0):  MU >= 113          n = 14
            H(A):  MU < 113           YBAR = 108
            ALPHA = .01               s**2 = 56

Back to this chapter's Contents

Look at the answer


2151-2

    Q:  Suppose that the heights of American males are normally distributed
        with MU=71". A random sample of n=100 university students has XBAR=72.5,
        S**2 =25.0. Can it be claimed at the ALPHA=.10 level of significance
        that university students have a higher average height than American
        males as a whole?

Back to this chapter's Contents

Look at the answer


2789-1

    Q:  Suppose a test was taken by 36  students  and  the  variance  of  the
        distribution  of  scores  was 100. It is desired to test H(O): MU>=80
        against H(1): MU<80, using ALPHA=.05 and z  as  the  test  statistic.
        (Assume  the population of test scores is normally distributed.) What
        ( to the nearest tenth) is  the  starting  point  of  the  region  of
        rejection in terms of XBAR values?

        a.  76.1
        b.  76.7
        c.  77.3
        d.  77.7
        e.  None of these.

Back to this chapter's Contents

Look at the answer


2790-1

    Q:  A fourth grade teacher wants to try a new teaching method which the
        authors recommend should only be used with particularly bright
        children.  The authors offer a short test which they feel can be
        used as a guide to decide whether the method should be used.  They
        believe that the average score for a class on this test should
        significantly exceed 73 and indicate that the national standard
        deviation for the test is 10.  The teacher's students take the test
        and exhibit the following scores:  91, 91, 94, 63, 61, 40, 73, 75, 83,
        84, 70, 71, 88, 93, 92, 91, 87, 83, 74, 80.

        Should the teacher use the new method?  Why?  (Use ALPHA = .05.)

Back to this chapter's Contents

Look at the answer


2792-1

    Q:  In  a  Cancer Experiment, Guinness Beer was given in large quantities
        to rats (fortunate things]) to see if  it  inhibited  the  growth  of
        tumors.  From comparative, comprehensive studies it is known that the
        "typical" tumor should weigh 1.35 grams.  These 25 rats  had  a  mean
        weight of 1.31 grams with a standard deviation of 0.2 grams.

        a.  Has there been a significant inhibiting of growth?  Use an ALPHA of
            0.10.  (Assume tumors are normally distributed.)

        b.  What is the smallest ALPHA-level that could be chosen before you
            would change your conclusion?

Back to this chapter's Contents

Look at the answer


2796-1

    Q:  The Crapi Cable Company #35 cable has a mean breaking strength of 1800
        pounds with a standard deviation of 100 pounds.  A new material is used
        which, it is claimed, increases the breaking strength.  To test this
        claim a random sample of 50 cables, manufactured with the new material,
        is tested.  It is found that the sample has a mean breaking strength
        of 1850 pounds.  Test this claim using ALPHA = .01.

Back to this chapter's Contents

Look at the answer


2799-1

    Q:  In the past a chemical fertilizer plant has produced  an  average  of
        1100 pounds of fertilizer per day. The record for the past year based
        on 256 operating days shows the following:

              XBAR = 1060 lbs/day
                 S =  320 lbs/day

        where  XBAR  and  S  have  the  usual  meaning. It is desired to test
        whether or not the average daily production has dropped significantly
        over  the  past  year.  Suppose  that  in this kind of operation, the
        traditionally acceptable level of significance has been .05. But  the
        plant manager, in his report to his bosses, uses level of significance
        .01. Analyze the data at both levels after setting up appropriate
        hypotheses, and comment.

Back to this chapter's Contents

Look at the answer


2800-1

    Q:  In J.B. Nimble's occupation, he  is  concerned  with  the  length  of
        candles.  Assuming  that candle lengths are normally distributed with
        mean MU and variance 4.0 square inches, he is interested  in  testing
        the hypothesis that MU <= 15.0 inches against the alternative that MU
        > 15.0 inches at a .001 significance  level.   For  a  sample  of  49
        candles, he obtains a sample mean of 15.6 inches.  Conclusions?

Back to this chapter's Contents

Look at the answer


2803-1

    Q:  It is desired to test the claim  that  a  steady  diet  of wolfbane will
        cause a lycanthrope (werewolf) to lose 10 lbs. over 5 months.  A  random
        sample of 49 lycanthropes was taken yielding an average weight loss over
        5 months of 12.5 pounds, with S = 7 lbs.  Use a two-tailed test and  let
        ALPHA = .02.

        Since the observed Z-value is _______ than the table value, we would ___
        H(0).  (Regard Z as an adequate approximation to t.)

        a.  smaller, reject
        b.  greater, not reject
        c.  greater, reject
        d.  smaller, not reject

Back to this chapter's Contents

Look at the answer


2808-1

    Q:  The Pfft Light Bulb Company claims that the mean life of its 2 watt
        bulbs is 1300 hours.  Suspecting that the claim is too high, Nalph
        Rader gathered a random sample of 64 bulbs and tested each.  He found
        the average life to be 1295 hours with s = 20 hours.  Test the com-
        pany's claim using ALPHA = .01.

Back to this chapter's Contents

Look at the answer


2811-2

    Q:  A study was conducted to see if  students  living  off-campus  had  a
        grade   point   average   which   differed   significantly  from  the
        university-wide average GPA of 2.65.  Extensive records indicate that
        the  standard  deviation of the GPA is 0.3.  What is your conclusion,
        if a random sample of 100 off-campus students had a mean GPA of 2.72?
        (The  researcher  feels  that  it  is  reasonable  to assume that the
        population of GPA  scores  is  normally  distributed.)  What  is  the
        significance probability of the observed result?

Back to this chapter's Contents

Look at the answer


Return to the list of chapters

Return to Brian Schott @ GSU

Answers:

124-2

    A:  e.  2.33

        t(critical,twotail,ALPHA=.02,df=48) == +/- 2.33

Back to review this question

Look at this question's identification

Back to this chapter's Contents


158-1

    A:  c)  92%, 1.75

Back to review this question

Look at this question's identification

Back to this chapter's Contents


209-1

    A:  Z(for ALPHA=.01) = 2.33
           Z = (XBAR - MU)/SIGMA
        2.33 = (8 - MU)/.3

        8 - MU = (2.33) (.3)
            MU = 8 - (.699)
            MU = 7.301

Back to review this question

Look at this question's identification

Back to this chapter's Contents


210-1

    A:  a.  One tail test at ALPHA = .01, therefore Z = 2.33.

            Z = (YBAR-MU)/(SIGMA/SQRT(n))
            2.33 = (YBAR-300)/(24/SQRT(64))
            YBAR = 307

            Decision Rule:  If the mean strength of 64 ropes tested is 307
                            lbs. or more, we reject the hypothesis of no im-
                            provement, i.e., we continue that the new process
                            is better.

        b.  If available, consult file of graphs and diagrams that could not
            be computerized for reference distributions.

            Z = (307-310)/(24/SQRT(64)) = 1.00
            Area = 0.1587 or 15.87%

            P(type II error) = 0.1587

Back to review this question

Look at this question's identification

Back to this chapter's Contents


720-3

    A:  a.  the null hypothesis is rejected when it is true.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


722-1

    A:  A.  the probability that the observed experimental
            difference is due to chance given the null hypothesis.
        C.  symbolized by the greek letter ALPHA.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


745-2

    A:  False.
        Level of confidence = 1 - (level of significance).

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1280-1

    A:  c.  2.5

        t(calculated) = (12.5-10)/(7/SQRT(49))
                      = 2.5

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1285-1

    A:  (a)  XBAR - 5 > 1.29 or 5 - XBAR > 1.29

             Half Confidence Interval = Z*SIGMA/SQRT(n)
                                      = 2.576 * .5 = 1.29

             Hence, the critical value at the 1% level is 1.29.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1287-2

    A:  (a)  XBAR >= 7.3

                Z = (XBAR- MU)/(S/SQRT(n))
            1.645 = (XBAR - 4)/2
             XBAR = 7.29

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1288-1

    A:  a.  .05

        Half Confidence Interval = Z * S/SQRT(N)
                              .5 = Z * 5/20
                               2 = Z
                   Area beyond Z = .023

        So for both tails the significance level used = .023 + .023 = .046

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1290-1

    A:  c)  reject, 2.2, outside of

            S**2 = 399/399 = 1
            S(XBAR) = SQRT(S**2/n) = .05

            If you center the confidence interval on the sample mean the
            confidence interval = 2 +/- (1.75)(.05)
                                = from 1.9125 to 2.0875

            which does not contain the hypothesized value, 2.2.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1291-1

    A:  e)  4%, reject, to the left of

            S**2 = 399/399 = 1;  S(XBAR) = SQRT(S**2/n) = .05;
            C.I. = 2 +/- Z(ALPHA/2) * .05;

            Z(16%/2) = 1.41, Z(8%/2) = 1.75, Z(4%/2) = 2.05

            C.I.(ALPHA=16%) = 2 +/- (1.41)(.05)
                            = from 1.93 to 2.07

            C.I.(ALPHA= 8%) = 2 +/- (1.75)(.05)
                            = from 1.91 to 2.09

            C.I.(ALPHA= 4%) = 2 +/- (2.05)(.05)
                            = from 1.90 to 2.10

            1 is not included in any of the confidence intervals, so H(0) should
            be rejected in all cases.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1298-1

    A:  b.  the result would be unexpected if the null hypothesis were true.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1298-2

    A:  d.  both (a) and (b).

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1299-2

    A:  d.  the sampling distribution of the statistic assuming H(O).

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1301-1

    A:  c.  the probability of getting a t-value >= 1.8 or <= -1.8.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1301-2

    A:  b.  I and either II or III.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1302-1

    A:  b.  I and II only

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1306-2

    A:  d)  Z < -1.96 or Z > 1.96

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1307-1

    A:  b)  H(O) is rejected.

            t(calc) = [XBAR - MU]/[s/SQRT(n)]
                    = [6.4 - 10]/[10/5]
                    = [-3.6]/2
  = -1.8

            t(crit., df=24, ALPHA=.05, one-tailed) = -1.711

            Since t(calc) < t(crit), reject H(O).  However, since the true
            value of MU is not known, we do not know if a type 1 error has
            been committed.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1308-1

    A:  a)  A correct decision.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1309-1

    A:  c)  The home owner is wrong, the house is worth less than $40,000.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1309-2

    A:  b.  It is the point where the decision changes from reject to fail to
            reject.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1312-1

    A:  (c)  must be decided by the investigator.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1313-3

    A:  c.  the sample data are not inconsistent with the hypothesis that in
            the population, MU = 50.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1323-1

    A:  H(O):  MU <= 155
        H(A):  MU  > 155

        ALPHA = .05          MU = 155          SIGMA = 10
        SIGMA(XBAR) = 10/SQRT(100) = 1

        Z(calculated) = (XBAR - MU)/SIGMA(XBAR)
                      = (170 - 155)/1
                      = 15

        Z(critical, ALPHA =.05, one-tailed) = 1.645

        Since Z(calculated) > Z(critical), reject H(O).  Conclude that the
        new bowling ball does improve a bowler's average at the 5% level.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1325-1

    A:  H(O):  MU >= 105
        H(A):  MU <  105

        t(obtained) = (XBAR - MU)/S(XBAR)
                    = (101.5 - 105)/1.42
                    = -3.5/1.42
                    = -2.465

        t(critical, ALPHA=.05, one-tail, df=29) = -1.699

        Since t(obtained) < t(critical), reject H(O).  Therefore, the sample
        evidence is strong enough to suggest that poor readers test signifi-
        cantly lower in IQ.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1336-4

    A:  The  main  objection  is  that  your  level  of  confidence  would be
        approximately equal to .10 while  the  significance  level  would  be
        approximately  equal  to  .90.  This situation is the reverse of most
        testing situations.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1349-3

    A:  False - A result may be significant at the 5% level, but not at
        the 1% level.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1352-1

    A:  False, the decision to use a one-sided or two-sided test should be
        made before the data is collected, so that the experimenter is not
        influenced by the data.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1352-3

    A:  True,  if  the  results  are  significant  at  .001 level, it is very
        unlikely (one in one thousand) that the null hypothesis is true.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1354-2

    A:  False, this statement is accurate only if the null hypothesis is true.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1489-1

    A:  H(O): MU =   7.10
        H(A): MU =/= 7.10

              YBAR = 7.07

              S(Y) = 0.0265

                 t = (YBAR - MU)/S(YBAR) = (7.07 - 7.10)/(0.0265/SQRT(5))
                   = 2.53

                 t(critical, ALPHA=.05, df=4) = +/- 2.776

        Since the calculated value of t is not in the critical region, continue
        H(O) that the nitrogen content has a true value of  7.10%,  i.e.,   the
        0.03% difference is ascribable to random error.

        or

        YBAR +/- t*(S(Y)/SQRT(n))
        YBAR +/- 2.776*(0.0265)/(SQRT(5))
        P(7.037 <= MU <= 7.103) = 0.95

        Continue H(O) that the nitrogen content has a true value of 7.10% at 95%
        level since 7.10 lies within the 95% confidence interval.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1490-1

    A:  a.  H(O):  MU = 10
            H(A):  MU < 10

            t(calculated) = (XBAR - MU)/(S(X)/SQRT(n)
                          = (8 - 10)/SQRT(2.5/5)
                          = -2/.707
                          = -2.8

            t(critical, one-tail, ALPHA = .05, df = 4) = -2.13

            Decision:  reject H(O) and conclude that this data does present
            sufficient indication, with confidence level = .95, that the mean
            reaction time of all people would be less than ten seconds.

        b.  C.I. = XBAR +/- t(ALPHA = .10)*S(XBAR)
                 = 8 +/- (2.13 * .707)
                 = 8 +/- 1.51

                6.49 < MU < 9.51

        c.  1.)  The sample of n=5 observations is a simple random sample
                 of times from the population or phenomena being studied.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1493-1

    A:  A. XBAR +/- Z*SIGMA/SQRT(n) = 70 +/- (1.96*3)/SQRT(25)
                                    = 66.824 to 71.176
        B. Not Reject H(0)
        C. Reject H(0)
        D. H(0): MU = 69 vs. H(1): MU > 69.
           Decision Rule: If Z obtained > Z critical then reject H(0).

                     Z (Calculated) = (XBAR - MU)/(SIGMA(XBAR))
                                    = (70-69)/.6 = 1.667
                       Z (Critical) = 1.645

                      1.667 > 1.645 => Reject H(0)

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1494-1

    A:  Yes, based on the above confidence interval, we would reject
            the hypothesis that MU = 700 (at ALPHA = .05).

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1502-2

    A:  H(0):  MU > 25
        H(1):  MU <= 25

        With ALPHA = .02, a one-tailed Z = 2.05
        Critical value = MU - (Z) (SIGMA(XBAR))
                       = 25  - (2.05)(1/SQRT(10))
                       = 24.35

        Decision rule:  If the sample mean is greater than or equal to 24.35,
        then the claim that MU > 25 is to be continued.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1508-1

    A:  a.       XBAR - t*SQRT((S**2)/n) <= MU <= XBAR + t*SQRT((S**2)/n)
            47000 - 2.06*SQRT(360000/25) <= MU <= 47000 + 2.06*SQRT(360000/25)
                                   46750 <= MU <= 47250

        b.  Physician incomes are normally distributed.  This is not likely to
            be a valid assumption - incomes are usually skewed.

        c.  The null hypothesis would be rejected since the hypothesized value
            of $50,000 is not included in the confidence interval found in (a.).

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1567-2

    A:  b.  I and either II or III

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1602-2

    A:  a.  MU > 20 with 5% chance of error

        t = (22-20)/(4/5) = 2.5
        Critical value for t is 1.711, with df = 24
        Reject H(0) and conclude H(A) is true with .05 chance of error.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1603-1

    A:  (a)  You would not reject H(O).

             The probability of the data under H(O) is greater than .25,
             therefore you would not reject H(O).

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1608-1

    A:  b.  reserve judgement about the hypothesis.

            S(XBAR) = S/SQRT(n)
                    = 9.0/SQRT(9)
                    = 3.0

            t(calc) = [XBAR - MU]/[S(XBAR)]
                    = [11.2 - 6.0]/[3.0]
                    = 1.73

            t(crit, df=8, ALPHA=.05, one-tail) = 1.86

            Since t(calc) < t(crit), continue (or do not reject) H(O).

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1609-1

    A:  b.  if the population mean MU is <= 6, the probability of deciding
            wrongly is at most 5%.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1610-3

    A:  b)  the same results would probably occur again.

            Statistical tests are always performed at some given probability
            level which gives the probability of occurrence of same results.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1617-1

    A:  b.  XBAR < 111.54

           SIGMA(XBAR) = SQRT(22.5/10)
                       = 1.5

        Critical point = 114 - (1.645)(1.5)
                       = 111.5325

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1618-1

    A:  b.  XBAR > 51.12 or XBAR < 34.88

            S/SQRT(n-1) = 7.5/3
                        = 2.5

            Critical points = 43 +/- t(df=9, ALPHA=.01/2)*(2.5)
                            = 43 +/- (3.25)(2.5)

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1619-1

    A:  b.  There is a significant difference in methods, p < .01.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1627-1

    A:  a.  H(O): MU =  225

        b.  H(A): MU <  225

        c.  t(calculated) = (210 - 225)/(30.9/SQRT(9))
                          = (-15)/(10.3)
                          = -1.456

        d.  t(critical, df = 8, ALPHA = .05, onetail) = -1.86

        e.  No

        f.  The result of this sample does not provide strong enough
            evidence to support the claim that cholesterol level was
            reduced.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1628-2

    A:  Using ALPHA = .05 and two-tailed t-test with df = 19,
        we test  H(0):  MU  =  13.5
                 H(1):  MU =/= 13.5

        t(calculated) = (11.6 - 13.5)/(5.49/SQRT(20)) = -1.55
        t(critical)   = +/- 2.093

        We conclude that, at the .05 ALPHA level, she should continue H(0),
        since the mean score of this class is not significantly different
        from the usual.  The basis for this conclusion rests on the assumption
        that the scores have a normal distribution.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1631-1

    A:  Using ALPHA = .05 and a one-tailed t-test we test:
            H(0):  MU <= 7600
            H(A):  MU >  7600

        t = (YBAR - MU)/(S(Y)/SQRT(N))
        t = (7638 - 7600)/(57.3/SQRT(10))
        t = 2.097

        t(critical) = 1.83

        Since t(calculated) is larger than t(critical) for a one-sided test at
        ALPHA = .05, reject the null hypothesis.  At the 95% confidence level,
        the sample evidence indicates a detectable increase.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1632-1

    A:  Null hypothesis:  MU =   170
            Alternative:  MU =/= 170
                       ALPHA =   .05

        Reject if t is not between -2.01 and 2.01.

        t = (160 - 170)/(11/SQRT(49))
          = -6.36

        Data from sample is not consistent with the assumption.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1635-1

    A:  H(O):  MU = 80
        H(A):  MU =/= 80

        SIGMA(XBAR) = SIGMA/SQRT(n)
                    = 7/5
                    = 1.4

        Using a Confidence Interval to test our hypothesis:

          XBAR(CRIT) = MU +/- Z(CRIT)*SIGMA(XBAR)
                     = 80 +/- 1.96*1.4
                     = 77.256 to 82.744

        Since 83 > 82.744 we reject H(O) and conclude that the result on the
        test is significantly different from 80.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1646-1

    A:  MU = 73.6
        SIGMA = 9
        Test the hypothesis that this years class is a sample of a
        population with MU = 73.6 and standard deviation = 9.
        H(0):  MU = 73.6
        H(1):  MU =/= 73.6
        SIGMA(XBAR) = 9/SQRT(20) = 2.01
        Z(calculated) = (77.3 - 73.6)/2.01
                      = 3.7/2.01
                      = l.84
        Z(critical) = 1.96 with ALPHA = .05
        At the 5% significance level, Z(calculated) is less than
        Z(critical) so based on this evidence I would conclude that
        this years class is not different from previous years classes.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1654-1

    A:  False.  A statistic significant at the 5% level is not necessarily
        significant at the 1% level, although the latter may be true.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1654-2

    A:  True.  In statistical inference  there  is always some probability, how-
        ever small, of drawing the wrong conclusion.  The fact that a hypothesis
        is consistent with a set of data does  not  mean  that  it  is  correct;
        whereas, if it is not consistent with the data set it may be incorrect.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1655-1

    A:  True, the purpose of a hypothesis test is to draw a conclusion about
        a population based on a sample.  If the population is known, there is
        nothing to hypothesize.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1655-2

    A:  False, if the assumed distribution is symmetric, the P-value can be
        used in a two-sided test by doubling it.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1655-3

    A:  False, the descriptive level of significance (P-value) is dependent
        on the sample.  The ALPHA level is chosen before the experiment is
        conducted.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1657-1

    A:  False.
        The failure to reject does not imply the null hypothesis is true.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1657-2

    A:  False.  A small significance level merely indicates that the probability
        of a type I error is small.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1657-3

    A:      True, 95% confidence automatically implies more than
        90% confidence.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1661-4

    A:  c.  rejecting the null hypothesis when it is true.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1662-1

    A:  c.  type 1 error

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1662-2

    A:  (c)  the old process is better when it is not.

             Type I Error = rejecting null hypothesis when it is true
                          = rejecting [newer is as good or better than old]
                            when true
                          = continuing [old better than new] when it is not
                          = Prob(getting old betternew process is better
                            than old one)

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1664-2

    A:  Usually, one would like the critical region for a test to be SHORT.
        The "size" of the critical region is determined by ALPHA.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1664-4

    A:  b.  unaffected

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1665-1

    A:  b.  unaffected.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1667-2

    A:  a.  .0207

            Area beyond Z corresponding to Z value of 2.04 = .0207.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1668-2

    A:  c.  +/- 1.645

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1669-1

    A:  b.  an unnecessary interruption of production.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1670-1

    A:  (1)  Type I error:  inconvenience in carrying needless rain equipment;
             Type II error: clothes get soaked.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1672-2

    A:  a.  true

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1677-1

    A:  a.  H(0):  MU = 140
            H(A):  MU =/= 140
            ALPHA = .05

            Test statistic:  Z = (XBAR-MU)/(SIGMA/SQRT(n))
            Assumptions:  Random sample.  Sampling distribution of mean is
                          normal.
            Critical region:  Z > 1.96 or Z < -1.96

            Z = (137-140)/(20/SQRT(400)) = -3.00
            Reject H(0)
            Conclude true mean is not equal to 140.

        b.  Type I error:  rejection of true H(0).  Probability is .05 (ALPHA).

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1686-3

    A:  False, a Type I error is committed when one rejects the null hypothesis
        when it is true.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1688-1

    A:  False - The significance level is computed under the
        assumption that the null hypothesis is true.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1688-2

    A:  False - The risk of type II error depends upon the risk of type I
        error.  As the risk of one type increases, the risk of the other type
        decreases.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1691-2

    A:  True.
        Level of significance is the probability of Type I error.  We would
        always like to have it small.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1693-1

    A:  True.
        Level of confidence = (1 - ALPHA).

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1694-1

    A:  True.

                       Reject H(0)               Don't Reject H(0)
                    ________________________________________________

                                                      NO ERROR
        H(0) True       TYPE1ERROR                    1 - ALPHA

                    ________________________________________________

        H(0) False      NO ERROR                     TYPE2ERROR
                        1 - BETA

                    ________________________________________________

        Therefore, either we can make a Type I error or Type II error
        depending on whether our hypothesis is true or false, but it is
        impossible to make both simultaneously.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1694-2

    A:  False, the level of significance is usually chosen before the
        measurements are collected and is not dependent on the sample
        size.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1702-1

    A:  (b)  to conclude that the process is not producing too many defec-
             tives when it actually is.

             Type II error = P(do not reject H(O) when H(O) is false)

                      H(O) = process producing no more than k defectives

                      H(O) false means process producing more than k de-
                      fectives.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1704-1

    A:  c.  not rejecting the null hypothesis when the alternative is
            true.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


1706-2

    A:  (5)  Cannot be determined without more information.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


2137-1

    A:  a.  t = -2.12

            With df = 16 - 1 = 15,

            t(critical, ALPHA = .05)  = -1.753
            t(critical, ALPHA = .025) = -2.131

Back to review this question

Look at this question's identification

Back to this chapter's Contents


2139-1

    A:  (b)  1.96

             This is a one-sided test and, since SIGMA is known,
             Z(ALPHA = .025) = 1.96.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


2140-1

    A:  a.  not reject H(0).

            t(calculated) = (701 - 680)/(50/SQRT(16))
                          = 21/(50/SQRT(16)) = 1.68

            t(critical, one tail, ALPHA = .05, df = 15) = 1.753
            Therefore t(calculated) < t(critical) and we should
            not reject H(0) at this significance level.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


2143-1

    A:  (4)  all of the above.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


2143-2

    A:  b.  5% probability of a type I error
            t = [XBAR - MU]/[S(XBAR)]
              = [3.48-3.80]/[[.80)/[SQRT(25)]]
              = -2.00, df = 25, one-tailed test

Back to review this question

Look at this question's identification

Back to this chapter's Contents


2147-1

    A:  a)  t(critical, df=26, ALPHA=.02, two-tail) = +/-2.479
            critical region: t's < -2.479 and t's > +2.479

            t(calculated) = (15-16)/SQRT(3/27)
                          = -3

            t(calculated) falls in the critical region, so based on this sample
            evidence you should reject H(0).

        b)  t(critical, df=249, ALPHA=.005, one-tail)
                            == Z(critical, ALPHA=.005, onetail) = +2.576
            critical region: Z's > +2.576

            Z(calculated) = (18.7-18.2)/(SQRT(3.6/250))
         = 4.166

            Z(calculated) falls in the critical region so based on this sample
            evidence you should reject H(0).

        c)  t(critical, df=13, ALPHA=.01, one-tail) = -2.65
            critical region:  t's < -2.65

            t(calculated) = (108-113)/(SQRT(56/14))
                          = -2.5

            t(calculated) does not fall in the critical region so based on this
            sample evidence do not reject (continue) H(0).

Back to review this question

Look at this question's identification

Back to this chapter's Contents


2151-2

    A:  Using a one-tail t-test, we test:
             H(0): MU<=71
             H(1): MU>71
        t(calculated) =(XBAR-MU)/(S/SQRT(n))
                      =1.5/(5/SQRT(100))
                      =3
        t(ALPHA=.10,df=99)==1.296

Back to review this question

Look at this question's identification

Back to this chapter's Contents


2789-1

    A:  c.  77.3

            Z(crit., ALPHA=.05, one-tail) = 1.645

            rejection region = MU - Z(crit.) * SIGMA/SQRT(n)
                             = 80 - (1.645 * 10/SQRT(36))
                             = 77.258

Back to review this question

Look at this question's identification

Back to this chapter's Contents


2790-1

    A:  H(0):  MU <= 73             SIGMA = 10
        H(1):  MU  > 73              XBAR = 79.2

        Z = (79.25 - 73)/(10/SQRT(20)) = 2.79

        Z(critical) = 1.645;  with ALPHA = .05 and using a onetail
                              decision rule.

        Reject H(0) and conclude that the average score for this class is
        significantly higher than 73.  Therefore, she should use the new
        method.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


2792-1

    A:  a.  H(O):  Guinness Beer does not affect tumors.
            H(A):  Guinness Beer inhibits the growth of tumors.

            i.e.,  H(O):  MU => 1.35
                   H(A):  MU <  1.35

            t(calc.) = [XBAR-MU]/[S/SQRT(n)]   with (n-1) df
                     = [1.31-1.35]/[0.2/SQRT(25)]
                     = [-0.04]/[0.04]
                     = -1.00

            t(crit., df=24, ALPHA=.10, one-tail) = -1.318

            Since t(calc.) > t(crit.), continue (do not reject) H(O).  It would
            thus appear that Guinness Beer does not affect the growth of tumors.

        b.  In part (a) we continued H(O), now we must reject H(O) for some
            level of ALPHA.  Keeping same degrees of freedom we notice:

                      ALPHA                   t(crit.)
                      -----                   --------
                       0.05                    -1.711
                       0.10                    -1.318
                       0.15                    -1.059
                       0.20                    -0.857
                       0.25                    -0.685

            Since t(calc.) = -1.000, the test is significant for ALPHA=0.20,
            but not significant for ALPHA=0.15.  The approximate significance
            level obtained by interpolation is about 0.16.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


2796-1

    A:  Hypothetical population:  All Crapi #35 cables made with the new
                                  material.
                         Sample:  The 50 cables randomly selected.

        H(O):  MU <= 1800. The mean breaking strength of the new cable is
                           1800 lb.
        H(A):  MU >  1800. The mean breaking strength of the new cable is
                           more than 1800 lb.

        MU(XBAR) = 1800 by H(O)

        SIGMA(XBAR) = SIGMA/SQRT(n)
                    = 100/SQRT(50)
                    = 14.142

        XBAR(crit)  = MU(XBAR) + Z(crit)*SIGMA(XBAR)
                    = 1800 + (2.33)*(14.142)
                    = 1832.951

        Since the sample mean breaking strength is 1850, which is greater than
        1832.51, we must reject H(O)  and  conclude  that  the  mean  breaking
        strength of the new cable is significantly more than 1800 lb.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


2799-1

    A:  H(O):  MU => 1100
        H(A):  MU <  1100

        Since n   = 256, use Z to approximate t.

        S(XBAR) = 320/SQRT(256)
                = 320/16
                = 20

        Z(calculated) = (1060 - 1100)/20
                      = -40/20
                      = -2

        Z(critical, ALPHA=.05, one-tailed) = 1.645

        Z(critical, ALPHA=.01, one-tailed) = 2.33

        Therefore,  H(0)  is rejected at ALPHA=.05 but not at ALPHA=.01.
        It appears that the manager is trying to pull  a  fast  one  on  his
        bosses  by  using  ALPHA=.01  and saying production has not dropped.
        However, if the traditional level of significance is used,  ALPHA=.05,
        there is evidence that indicates a drop in production.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


2800-1

    A:      XBAR = 15.6
        SIGMA**2 = 4
               n = 49

        H(O):  MU <= 15.0
        H(A):  MU >  15.0

        ALPHA = .001
      Critical Region:  Z > 3.090

        Z(calculated) = (XBAR - MU)/(SIGMA/SQRT(n))
                      = 2.1

        Conclusion:  Mean candle lengths may be 15 inches.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


2803-1

    A:  c.  greater, reject

        Z(calculated) = (12.5-10)/(7/SQRT(49))
                      = 2.5/1
                      = 2.5

        Z(critical,ALPHA=.02,twotail) = +/- 2.33

Back to review this question

Look at this question's identification

Back to this chapter's Contents


2808-1

    A:  Hypothetical population:  All Pfft 2 watt bulbs.
                         Sample:  The 64 randomly selected bulbs.

        H(O):  MU => 1300. The mean life of 2 watt bulbs is 1300 hours.
        H(A):  MU <  1300. The mean life of 2 watt bulbs is less than 1300
                           hours.

        MU(XBAR)   = 1300 by H(O)

         S(XBAR)   = S/SQRT(n)
                   = 20/8
                   = 2.5

        XBAR(crit) = MU(XBAR) + Z(crit)*S(XBAR)
                   = 1300 - 2.33*2.5
                   = 1294.18

        Since 1295 is not less than 1294.18, we cannot reject H(O).  There is
        not enough evidence to conclude that the mean life of the 2 watt bulbs
        is significantly less than 1300 hours.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


2811-2

    A:     MU = 2.65
        SIGMA = 0.3
            N = 100
         XBAR = 2.72

        H(O):  MU(off-campus)  =  2.65
        H(A):  MU(off-campus) =/= 2.65

        Z(calculated) = (XBAR - MU)/(SIGMA/SQRT(100))
                      = 2.33

        P(Z > 2.33 or Z < -2.33) = .02

        Based on this sample evidence, it appears that the null hypothesis
        is incorrect and that off-campus students do have a different GPA.

Back to review this question

Look at this question's identification

Back to this chapter's Contents


Return to the list of chapters

Return to Brian Schott @ GSU

Identification:

124-2

Based upon item submitted by F. J. Samaniego - UC Davis
        Multiple Choice
TSCORE            TESTING           TWOTAIL/T
        STANDUNITS/NORMA  PROBDISTRIBUTION  PROBABILITY
        CONCEPT           STATISTICS        TTEST
        PARAMETRIC

T= 2    Comprehension
D= 2    General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


158-1

Based upon item submitted by F. J. Samaniego - UC Davis
        Multiple Choice
TESTING           SIMPLE/CI         ZSCORE
        CONCEPT           STATISTICS        CONFIDENCEINTERV
        ESTIMATION        STANDUNITS/NORMA  PROBDISTRIBUTION
        PROBABILITY

T= 2    Comprehension
D= 2    Natural Sciences    General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


209-1

Item is still being reviewed
        Numerical Answer
ZSCORE
        SIMPLE/CI         ONETAIL/Z         STANDUNITS/NORMA
        PROBDISTRIBUTION  PROBABILITY       CONFIDENCEINTERV
        ESTIMATION        CONCEPT           STATISTICS
        ZTEST             PARAMETRIC

T= 5    Application
D= 6    General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


210-1

Based upon item submitted by A. Bugbee - UNH
      Numerical Answer
TYPE2ERROR        TESTING           ZSCORE
        I650I             CONCEPT           STATISTICS
        STANDUNITS/NORMA  PROBDISTRIBUTION  PROBABILITY

T=15    Application
D= 5    General             Business            Natural Sciences
                ***Multiple Parts***

Back to review this question

Back to this chapter's Contents


720-3

Item is still being reviewed
        Multiple Choice
TYPE1ERROR        BASICTERMS/STATS
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


722-1

Item is still being reviewed
        Multiple Choice
TESTOFSIGNIFICAN  BASICTERMS/STATS
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


745-2

Based upon item submitted by J. L. Mickey -UCLA
        True/False
BASICTERMS/STATS  TYPE1ERROR
        STATISTICS        CONCEPT

T= 2    Comprehension
D= 2    General

Back to review this question

Back to this chapter's Contents


1280-1

Item is still being reviewed
        Multiple Choice
TESTING           TWOTAIL/T
        CONCEPT           STATISTICS        TTEST
        PARAMETRIC

T= 2    Computation
D= 3    General

Back to review this question

Back to this chapter's Contents


1285-1

Based upon item submitted by F. J. Samaniego - UC Davis
        Multiple Choice
SIMPLE/CI         TESTING
        CONFIDENCEINTERV  ESTIMATION        CONCEPT
        STATISTICS

T=10    Computation
D= 4    General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1287-2

Based upon item submitted by F. J. Samaniego - UC Davis
        Multiple Choice
TESTING           TESTOFSIGNIFICAN
        CONCEPT           STATISTICS

T= 5    Computation
D= 4    General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1288-1

Based upon item submitted by F. J. Samaniego - UC Davis
        Multiple Choice
TESTING           TESTOFSIGNIFICAN
        TYPE1ERROR        CONCEPT           STATISTICS

T= 5    Computation
D= 4    General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1290-1

Based upon item submitted by F. J. Samaniego - UC Davis
        Multiple Choice
TESTING           SIMPLE/CI
        ZSCORE            CONCEPT           STATISTICS
        CONFIDENCEINTERV  ESTIMATION        STANDUNITS/NORMA
        PROBDISTRIBUTION  PROBABILITY

T=10    Application
D= 4    General             Natural Sciences
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1291-1

Item is still being reviewed
        Multiple Choice
TESTING           SIMPLE/CI
        ZSCORE            CONCEPT           STATISTICS
        CONFIDENCEINTERV  ESTIMATION        STANDUNITS/NORMA
        PROBDISTRIBUTION  PROBABILITY

T=10    Application
D= 4    Natural Sciences    General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1298-1

Based upon item submitted by J. L. Mickey -UCLA
        Multiple Choice
TESTING           TYPE1ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 2    General

Back to review this question

Back to this chapter's Contents


1298-2

Based upon item submitted by J. L. Mickey -UCLA
        Multiple Choice
TESTING
        CONCEPT           STATISTICS

T= 2    Computation
D= 3    General

Back to review this question

Back to this chapter's Contents


1299-2

Item is still being reviewed
        Multiple Choice
TESTING
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1301-1

Item is still being reviewed
        Multiple Choice
TESTING           OTHER/T
        CONCEPT           STATISTICS        TTEST
        PARAMETRIC

T= 2    Comprehension
D= 2    General

Back to review this question

Back to this chapter's Contents


1301-2

Based upon item submitted by J. Inglis
        Multiple Choice
TESTING           TESTOFSIGNIFICAN
        MEAN              CENTRALLIMITTHM   CONCEPT
        STATISTICS        DESCRSTAT/P       PARAMETRIC

T= 5    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1302-1

Item is still being reviewed
        Multiple Choice
TYPE1ERROR        TESTING
        CONCEPT           STATISTICS

T= 5    Comprehension
D= 5    General

Back to review this question

Back to this chapter's Contents


1306-2

Item is still being reviewed
        Multiple Choice
TESTING           TWOTAIL/Z
        CONCEPT           STATISTICS        ZTEST
        PARAMETRIC

T= 2    Comprehension
D= 3    General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1307-1

Item is still being reviewed
        Multiple Choice
ONETAIL/T         TESTING
        TYPE1ERROR        TTEST             PARAMETRIC
        STATISTICS        CONCEPT

T= 5    Application     Computation
D= 3    General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1308-1

Item is still being reviewed
        Multiple Choice
TESTING
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1309-1

Item is still being reviewed
        Multiple Choice
TESTING
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 2    Business            General

Back to review this question

Back to this chapter's Contents


1309-2

Item is still being reviewed
        Multiple Choice
TESTING
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 2    General

Back to review this question

Back to this chapter's Contents


1312-1

Item is still being reviewed
        Multiple Choice
TESTING
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1313-3

Item is still being reviewed
        Multiple Choice
TESTING
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 4    General

Back to review this question

Back to this chapter's Contents


1323-1

Item is still being reviewed
        Numerical Answer
TESTING           ONETAIL/Z
        CONCEPT           STATISTICS        ZTEST
        PARAMETRIC

T=10    Computation
D= 5    General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1325-1

Item is still being reviewed
      Numerical Answer
TESTING           ONETAIL/T
        CONCEPT           STATISTICS        TTEST
        PARAMETRIC

T=10    Computation
D= 4    General             Psychology          Social Sciences
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1336-4

Item is still being reviewed
        Short Answer
TYPE1ERROR        TESTING
        CONCEPT           STATISTICS

T= 5    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1349-3

Based upon item submitted by W. J. Hall - Univ. of Rochester
        True/False
TESTOFSIGNIFICAN  TESTING
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1352-1

Based upon item submitted by J. L. Mickey -UCLA
        True/False
TESTING
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1352-3

Based upon item submitted by J. L. Mickey -UCLA
        True/False
TYPE1ERROR        TESTING
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1354-2

Based upon item submitted by J. L. Mickey -UCLA
        True/False
TYPE1ERROR        TESTING
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1489-1

Item is still being reviewed
        Short Answer
TESTOFSIGNIFICAN  SIMPLE/CI         TWOTAIL/T
        CONCEPT           STATISTICS        CONFIDENCEINTERV
        ESTIMATION        TTEST             PARAMETRIC

T= 5    Application     Computation
D= 3    Natural Sciences
                ***Calculator Necessary***
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1490-1

Based upon item submitted by R. E. Lund - Montana State U.
        Short Answer
ONETAIL/T         STANDERROROFMEAN  SIMPLE/CI
        TESTOFSIGNIFICAN  TTEST             PARAMETRIC
        STATISTICS        DESCRSTAT/P       CONFIDENCEINTERV
        ESTIMATION        CONCEPT

T= 6    Comprehension
D= 4    Psychology          General
                ***Calculator Necessary***
                ***Multiple Parts***
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1493-1

Based upon item submitted by W. J. Hall - Univ. of Rochester
        Short Answer
TWOTAIL/T         ONETAIL/T         SIMPLE/CI
        TESTING           TTEST             PARAMETRIC
        STATISTICS        CONFIDENCEINTERV  ESTIMATION
        CONCEPT

T=15    Application
D= 7    General
                ***Calculator Necessary***
                ***Multiple Parts***
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1494-1

Based upon item submitted by R. E. Lund - Montana State U.
        Short Answer
SIMPLE/CI
        CONFIDENCEINTERV  ESTIMATION        CONCEPT
        STATISTICS

T= 3    Comprehension   Computation
D= 4    Business            General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1502-2

Item is still being reviewed
        Short Answer
ONETAIL/Z         SIMPLE/CI
        TYPE1ERROR        STANDERROROFMEAN  TESTING
        I650I             ZTEST             PARAMETRIC
        STATISTICS        CONFIDENCEINTERV  ESTIMATION
        CONCEPT           DESCRSTAT/P

T=10    Comprehension
D= 5    General
                ***Calculator Necessary***
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1508-1

Item is still being reviewed
        Short Answer
SIMPLE/CI
        TTEST             TESTOFSIGNIFICAN  CONFIDENCEINTERV
        ESTIMATION        CONCEPT           STATISTICS
        PARAMETRIC

T=10    Computation     Comprehension
D= 4    General             Biological Sciences Economics
                ***Multiple Parts***
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1567-2

Item is still being reviewed
        Multiple Choice
ZTEST             ASSUMPTCUSTOMARY  CENTRALLIMITTHM
        TESTING           PARAMETRIC        STATISTICS
        MISCELLANEOUS     CONCEPT

T= 5    Comprehension
D= 4    General

Back to review this question

Back to this chapter's Contents


1602-2

Item is still being reviewed
        Multiple Choice                ***Calculus Necessary***
TESTOFSIGNIFICAN  ONETAIL/T
        CONCEPT           STATISTICS        TTEST
        PARAMETRIC

T= 5    Computation     Comprehension
D= 4    General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1603-1

Item is still being reviewed
        Multiple Choice                ***Calculus Necessary***
TESTOFSIGNIFICAN
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1608-1

Item is still being reviewed
        Multiple Choice
ONETAIL/T         TESTOFSIGNIFICAN
        TTEST             PARAMETRIC        STATISTICS
        CONCEPT

T= 5    Application
D= 4    Biological Sciences General
                ***Calculator Necessary***
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1609-1

Item is still being reviewed
        Multiple Choice
TESTOFSIGNIFICAN  ONETAIL/T
        CONCEPT           STATISTICS        TTEST
        PARAMETRIC

T= 2    Application
D= 2    General

Back to review this question

Back to this chapter's Contents


1610-3

Based upon item submitted by R. Shavelson - UCLA
        Multiple Choice
TESTOFSIGNIFICAN  TYPE1ERROR
        BASICTERMS/STATS  CONCEPT           STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1617-1

Based upon item submitted by F. J. Samaniego - UC Davis
        Multiple Choice
TESTOFSIGNIFICAN  STANDERROROFMEAN
        CONCEPT           STATISTICS        DESCRSTAT/P
        PARAMETRIC

T= 5    Computation
D= 3    General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1618-1

Item is still being reviewed
        Multiple Choice
TESTOFSIGNIFICAN  STANDERROROFMEAN
        CONCEPT           STATISTICS        DESCRSTAT/P
        PARAMETRIC

T= 5    Application
D= 3    General

Back to review this question

Back to this chapter's Contents


1619-1

Based upon item submitted by G. Shavlik - Loma Linda Univ.
        Multiple Choice
TWOTAIL/T         TESTOFSIGNIFICAN
        TTEST             PARAMETRIC        STATISTICS
        CONCEPT

T= 2    Comprehension
D= 3    General             Biological Sciences
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1627-1

Item is still being reviewed
        Numerical Answer
ONETAIL/T         TESTOFSIGNIFICAN
        TTEST             PARAMETRIC        STATISTICS
        CONCEPT

T=10    Application
D= 4    Biological Sciences General
                ***Multiple Parts***
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1628-2

Item is still being reviewed
        Numerical Answer
TWOTAIL/T         TESTOFSIGNIFICAN
        STANDERROROFMEAN  I650I             TTEST
        PARAMETRIC        STATISTICS        CONCEPT
        DESCRSTAT/P

T= 5    Application
D= 5    Education           General
                ***Calculator Necessary***
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1631-1

Item is still being reviewed
        Short Answer
ONETAIL/T         TESTOFSIGNIFICAN
        STANDERROROFMEAN  SIMPLEDATASET     I650I
        TTEST             PARAMETRIC        STATISTICS
        CONCEPT           DESCRSTAT/P

T= 5    Application
D= 4    Natural Sciences
                ***Calculator Necessary***
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1632-1

Item is still being reviewed
        Short Answer
TWOTAIL/Z         TESTOFSIGNIFICAN
        TESTING           ZTEST             PARAMETRIC
        STATISTICS        CONCEPT

T=10    Application
D= 4    Biological Sciences General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1635-1

Item is still being reviewed
        Short Answer
TESTOFSIGNIFICAN  TWOTAIL/Z
        CONCEPT           STATISTICS        ZTEST
        PARAMETRIC

T=10    Computation
D= 2    General             Education
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1646-1

Item is still being reviewed
        Short Answer
TWOTAIL/Z         TESTOFSIGNIFICAN
        STANDERROROFMEAN  I650I             ZTEST
        PARAMETRIC        STATISTICS        CONCEPT
        DESCRSTAT/P

T=10    Application
D= 4    Education           General
                ***Calculator Necessary***
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1654-1

Based upon item submitted by D. Kleinbaum - Univ of North Carolina
        True/False
TESTOFSIGNIFICAN
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1654-2

Based upon item submitted by D. Kleinbaum - Univ of North Carolina
        True/False
TESTOFSIGNIFICAN
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1655-1

Based upon item submitted by D. Kleinbaum - Univ of North Carolina
        True/False
TESTOFSIGNIFICAN  SCOPEOFINFERENCE
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 5    General

Back to review this question

Back to this chapter's Contents


1655-2

Item is still being reviewed
        True/False
TESTOFSIGNIFICAN
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1655-3

Based upon item submitted by D. Kleinbaum - Univ of North Carolina
        True/False
TESTOFSIGNIFICAN
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 5    General

Back to review this question

Back to this chapter's Contents


1657-1

Item is still being reviewed
        True/False
TESTOFSIGNIFICAN  TYPE1ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 4    General

Back to review this question

Back to this chapter's Contents


1657-2

Item is still being reviewed
        True/False
TESTOFSIGNIFICAN  TYPE1ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 2    General

Back to review this question

Back to this chapter's Contents


1657-3

Based upon item submitted by A. Bugbee - UNH
        True/False
TESTOFSIGNIFICAN
        TYPE1ERROR        CONFIDENCEINTERV  CONCEPT
        STATISTICS        ESTIMATION

T= 2    Comprehension
D= 1    General

Back to review this question

Back to this chapter's Contents


1661-4

Based upon item submitted by R. Pruzek - SUNY at Albany
        Multiple Choice
TYPE1ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 4    General

Back to review this question

Back to this chapter's Contents


1662-1

Item is still being reviewed
        Multiple Choice
TYPE1ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 1    General

Back to review this question

Back to this chapter's Contents


1662-2

Based upon item submitted by S. Sytsma - Ferris State
        Multiple Choice
TYPE1ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 2    General

Back to review this question

Back to this chapter's Contents


1664-2

Based upon item submitted by J. L. Mickey -UCLA
        Multiple Choice
TYPE1ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 2    General
                ***Multiple Parts***

Back to review this question

Back to this chapter's Contents


1664-4

Item is still being reviewed
        Multiple Choice
TYPE1ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1665-1

Based upon item submitted by S. Selvin - UC Berkeley
        Multiple Choice
TYPE1ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1667-2

Item is still being reviewed
        Multiple Choice
TYPE1ERROR        ONETAIL/Z
        CONCEPT           STATISTICS        ZTEST
        PARAMETRIC

T= 2    Computation     Comprehension
D= 2    General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1668-2

Item is still being reviewed
        Multiple Choice
TWOTAIL/Z         TYPE1ERROR
        ZTEST             PARAMETRIC        STATISTICS
        CONCEPT

T= 2    Comprehension
D= 2    General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1669-1

Item is still being reviewed
        Multiple Choice
TYPE1ERROR
        CONCEPT           STATISTICS

T= 5    Comprehension
D= 3    Natural Sciences    Business            General

Back to review this question

Back to this chapter's Contents


1670-1

Item is still being reviewed
        Multiple Choice
TYPE1ERROR        TYPE2ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension   Application
D= 4    General

Back to review this question

Back to this chapter's Contents


1672-2

Item is still being reviewed
        Multiple Choice
TYPE1ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1677-1

Item is still being reviewed
        Short Answer                   ***Calculus Necessary***
TWOTAIL/Z         TYPE1ERROR
        ZTEST             PARAMETRIC        STATISTICS
   CONCEPT

T=10    Application     Comprehension
D= 4    General             Biological Sciences
                ***Multiple Parts***
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


1686-3

Item is still being reviewed
        True/False
TYPE1ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 4    General

Back to review this question

Back to this chapter's Contents


1688-1

Based upon item submitted by W. J. Hall - Univ. of Rochester
        True/False
TYPE1ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 2    General

Back to review this question

Back to this chapter's Contents


1688-2

Based upon item submitted by W. J. Hall - Univ. of Rochester
        True/False
TYPE1ERROR        TYPE2ERROR
        CONCEPT           STATISTICS

T= 5    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1691-2

Item is still being reviewed
        True/False
TYPE1ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1693-1

Item is still being reviewed
   True/False
TYPE1ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 2    General

Back to review this question

Back to this chapter's Contents


1694-1

Item is still being reviewed
        True/False
TYPE1ERROR        TYPE2ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 4    General

Back to review this question

Back to this chapter's Contents


1694-2

Based upon item submitted by J. L. Mickey -UCLA
        True/False
TYPE1ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 2    General

Back to review this question

Back to this chapter's Contents


1702-1

Item is still being reviewed
        Multiple Choice
TYPE2ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 2    General

Back to review this question

Back to this chapter's Contents


1704-1

Item is still being reviewed
        Multiple Choice
TYPE2ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


1706-2

Item is still being reviewed
        Multiple Choice
TYPE2ERROR
        CONCEPT           STATISTICS

T= 2    Comprehension
D= 2    General

Back to review this question

Back to this chapter's Contents


2137-1

Item is still being reviewed
        Multiple Choice
ONETAIL/T
        TTEST             PARAMETRIC        STATISTICS

T= 2    Comprehension
D= 3    General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


2139-1

Item is still being reviewed
        Multiple Choice
ONETAIL/T
        TTEST             PARAMETRIC        STATISTICS

T= 2    Computation
D= 2    General

Back to review this question

Back to this chapter's Contents


2140-1

Based upon item submitted by F. J. Samaniego - UC Davis
        Multiple Choice
ONETAIL/T
        TTEST             PARAMETRIC        STATISTICS

T= 5    Application
D= 3    General             Biological Sciences
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


2143-1

Item is still being reviewed
        Multiple Choice
ONETAIL/T
        TTEST             PARAMETRIC        STATISTICS

T= 2    Comprehension
D= 3    General

Back to review this question

Back to this chapter's Contents


2143-2

Item is still being reviewed
        Multiple Choice
ONETAIL/T
        TTEST             PARAMETRIC        STATISTICS

T= 2    Computation
D= 3    Biological Sciences General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


2147-1

Item is still being reviewed
        Numerical Answer
ONETAIL/T         TWOTAIL/T
        TTEST             PARAMETRIC        STATISTICS

T=10    Computation     Application
D= 5    General
                ***Calculator Necessary***
                ***Multiple Parts***
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


2151-2

Based upon item submitted by W. J. Hall - Univ. of Rochester
        Short Answer
ONETAIL/T
        STANDERROROFMEAN  TESTOFSIGNIFICAN  I650I
        TTEST             PARAMETRIC        STATISTICS
        DESCRSTAT/P       CONCEPT

T= 5    Application
D= 5    Biological Sciences General             General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


2789-1

Item is still being reviewed
        Multiple Choice
ONETAIL/Z
        ZTEST             PARAMETRIC        STATISTICS

T= 5    Application
D= 4    General             Education
                ***Calculator Necessary***
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


2790-1

Item is still being reviewed
        Numerical Answer
ONETAIL/Z
        STANDERROROFMEAN  I650I             ZTEST
        PARAMETRIC        STATISTICS        DESCRSTAT/P

T=10    Application
D= 4    Education
                ***Calculator Necessary***
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


2792-1

Item is still being reviewed
        Numerical Answer
ONETAIL/Z
        ZTEST             PARAMETRIC        STATISTICS

T=10    Application
D= 4    General             Biological Sciences
                ***Multiple Parts***
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


2796-1

Item is still being reviewed
        Short Answer
ONETAIL/Z
        ZTEST             PARAMETRIC        STATISTICS

T=10    Computation
D= 2    General             Business
                ***Calculator Necessary***
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


2799-1

Item is still being reviewed
        Short Answer
ONETAIL/Z
        COMMONPITFALLS    ZTEST             PARAMETRIC
        STATISTICS        MISCELLANEOUS

T=10    Application
D= 4    Business            Natural Sciences    General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


2800-1

Item is still being reviewed
        Short Answer
ONETAIL/Z
        MEAN              ZTEST             PARAMETRIC
        STATISTICS        DESCRSTAT/P

T=10    Application
D= 4    General

Back to review this question

Back to this chapter's Contents


2803-1

Based upon item submitted by F. J. Samaniego - UC Davis
        Multiple Choice
TWOTAIL/Z
        ZTEST             PARAMETRIC        STATISTICS

T= 5    Comprehension   Computation
D= 3    General
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


2808-1

Item is still being reviewed
        Short Answer
TWOTAIL/Z
        ZTEST             PARAMETRIC        STATISTICS

T=10    Computation
D= 2    General             Business
                ***Statistical Table Necessary***

Back to review this question

Back to this chapter's Contents


2811-2

Item is still being reviewed
        Short Answer
TWOTAIL/Z
        MEAN              ZTEST             PARAMETRIC
        STATISTICS        DESCRSTAT/P

T=10    Application
D= 4    General             Education

Back to review this question

Back to this chapter's Contents


Return to the list of chapters

Return to Brian Schott @ GSU