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Chapter 16: Statistical Testing of Differences and Relationships
Multiple Choice
1. In statistical testing, if a difference between two groups is large enough to be unlikely
because of chance, we say that this difference is:
a. statistically insignificant.
b. a chance occurrence.
c. statistically significant.
d. due to sampling error.
e. a spurious occurrence.
2. The statement: “If we lower the price of this product by 5 percent, then our profit will
increase by 3 percent” represents what type of statement?
a. A wild guess
b. A conclusion
c. A faint hope
d. A hypothesis
e. A decision rule
3. If McDonald’s sets a standard that orders from the drive-in of a restaurant should be
presented to the customers within three minutes of the order, then the statement: “The
average waiting time for drive-in orders at the Webster Groves McDonald’s is three
minutes” represents what type of statement?
a. A null hypothesis
b. A research hypothesis of interest
c. A research hypothesis
d. An independent sample
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e. An alternative hypothesis
4. When the null hypothesis of a statistical test is rejected when, in fact, it is true, this
represents a(n):
a. Beta error
b. Type I error
c. Type IV error
d. Type III error
e. Type II error
5. When a researcher fails to reject the null hypothesis of a statistical test when, in fact, it is
false, this represents a(n):
a. Alpha error.
b. Type I error.
c. Type IV error.
d. Type III error.
e. Type II error.
6. Suppose that a researcher wants to check to see if the average household income in
Webster Groves, Missouri, has changed from the $60,000 it was three years ago. The
researcher takes a random sample of households in Webster Groves and finds that the
average income of these households is $58,000. If the standard error of the mean for this
sample is $500, what is the approximate value produced by the Z-test?
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a. + 4.00
b. + 3.65
c. +2.00
d. ─ 4.00
e. ─ 3.65
7. Suppose that a researcher wants to check to see if the average household income in
Webster Groves, Missouri, has changed from the $60,000 it was three years ago. The
researcher takes a random sample of households in Webster Groves and finds that the
average income of these households is $58,000. If the standard error of the mean for this
sample is $500, what is the approximate conclusion produced by the Z-test if the critical
Z-value is 1.96?
a. Accept the null hypothesis
b. Reject the research hypothesis of interest
c. Accept the hypothesis of the status quo
d. Reject the null hypothesis and accept the research hypothesis
e. Reject the research hypothesis
8. When the measurement of a variable in one sample has no effect on the measurement of
this variable in another sample, we say that the samples are:
a. spurious.
b. dependent.
c. not independent.
d. related.
e. independent.
9. Another name for the chi-square test is the test of the ______________ .
a. goodness of fit.
b. two group t-test.
c. one-group t-test.
d. two group Z-test.
e. one-group Z test.
10. In a study comparing adult men and adult women, if the standard deviation of the group
of 49 men is 5.3 while the standard deviation of the 64 women is 4.8, what is the
approximate standard error of the difference of the means for these data?
a. 0.55
b. 0.67
c. 0.97
d. 0.78
e. 0.86
11. In a study comparing adult men and adult women, if the mean score of the men is 4.5 and
the mean score of the women is 6.5, and if the standard deviation of the group
of 49 men is 5.3 while the standard deviation of the 64 women is 4.8, what is the
approximate value of the Z-test result for these data?
a. + 2.64
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b. ─ 2.06
c. + 4.32
d. ─ 4.32
e. + 2.84
12. Suppose that you wanted to know if the “favorability rating” of the Mayor of St. Louis
was still at 65 percent when this survey question was asked three months ago. If the
sample size of your study is to be 200 registered voters, what is the approximate value of
the standard error of the proportion for these data?
a. 0.001
b. 0.534
c. 0.005
d. 0.034
e. 0.386
13. If a researcher wanted to determine if three different prices in three different test market
cities produced a significant difference in the number of units of a new shampoo that
were sold during the test market study, what type of statistical test should this researcher
use?
a. Chi-square
b. One-group t-test
c. Multiple regression
d. ANOVA
e. Two-group t-test
14. If there are four experimental groups in an ANOVA test, how many degrees of freedom
are thee in this study?
a. Three
b. Four
c. Five
d. One
e. Two
15. Another term for the ANOVA test is the:
a. One-group t-test.
b. F-test.
c. Multiple Regression test.
d. Two-group t-test.
e. Chi-square test.
True/False
16. Numbers that are mathematically different are always significantly different in a
statistical sense.
17. A statistical difference is important from a manager’s viewpoint only if the difference is
“sufficiently different.”
18. In statistical testing, Type I errors and Type II errors are complementary.
19. The null hypothesis is assumed to be true until there is sufficient evidence that it is likely
to be false.
20. The Z-test is typically used for large samples that have greater than 30 respondents, while
the t-test is typically used for small samples that have less than 30 respondents.