Chapter 10: Hypothesis Tests Involving Two Population Means or Proportions

Test Bank

Multiple Choice

1. This chapter focused upon the difference between two sample means uses and independent variable that is a ______ variable and a dependent variable that is a ______ variable

a. continuous; continuous

b. continuous; binary

c. binary; continuous

d. three or more level categorical; continuous

Learning Objective: 10.1. Identify the appropriate sampling distribution to use for a hypothesis test for large samples when you have a two-category independent variable and an interval- or ratio-level dependent variable.

Cognitive Domain: Knowledge

Answer Location: Explaining the difference between two sample means

Difficulty Level: Easy

2. Which question is this chapter most suited to answer?

a. Is there a difference in the average number of crimes committed between men and women?

b. Is there a difference in the average number of crimes committed between republicans, democrats, and independents?

c. Is there a difference in the average number of crimes committed between White, Black, and Hispanic men?

d. Is there a difference in the average number of crimes committed between White, Black, and Hispanic women?

Learning Objective: 10.1. Identify the appropriate sampling distribution to use for a hypothesis test for large samples when you have a two-category independent variable and an interval- or ratio-level dependent variable.

Cognitive Domain: Comprehension

Answer Location: Explaining the difference between two sample means

Difficulty Level: Easy

3. The sampling distribution of sample mean differences is the theoretical differences between ______.

a. 10,000 sample means

b. 100,000 sample means

c. only the sample means we collected

d. an infinite number of sample means

Learning Objective: 10.1. Identify the appropriate sampling distribution to use for a hypothesis test for large samples when you have a two-category independent variable and an interval- or ratio-level dependent variable.

Cognitive Domain: Knowledge

Answer Location: Sampling distributions of mean differences

Difficulty Level: Easy

4. The z-test for two means is appropriate whenever the two population variances () are ______.

a. unknown

b. known

c. normally distributed

d. beyond the critical value for statistical significance

Learning Objective: 10.2. Explain why you must use a slightly different hypothesis test when you cannot assume the variances for two groups are equal.

Cognitive Domain: Knowledge

Answer Location: Sampling distributions of mean differences

Difficulty Level: Medium

5. The t-test for two means is appropriate whenever the two population variances () are ______.

a. unknown

b. known

c. normally distributed

d. beyond the critical value for statistical significance

Learning Objective: 10.2. Explain why you must use a slightly different hypothesis test when you cannot assume the variances for two groups are equal.

Cognitive Domain: Knowledge

Answer Location: Sampling distributions of mean differences

Difficulty Level: Medium

6. Independent random samples are ______.

a. random, with an unknown probability of being selected, and independent of the other sample

b. random, with a known probability of being selected, and independent of the other sample

c. varying depending on the values of the other sample

d. come from the same population distribution as the other sample.

Learning Objective: 10.3. Describe the difference between independent groups and matched groups.

Cognitive Domain: Knowledge

Answer Location: Testing a hypothesis about the difference between two me

Learning Objective: 10.3. Describe the difference between independent groups and matched groups.

Cognitive Domain: Comprehension

Answer Location: Testing a hypothesis about the difference between two me

Learning Objective: 10.2. Explain why you must use a slightly different hypothesis test when you cannot assume the variances for two groups are equal.

Cognitive Domain: Knowledge

Answer Location: When we can assume equal variances: Pooled variance estimate

Difficulty Level: Easy

9. If one cannot assume that two unknown population standard deviations are equal, we estimate the standard error of the difference using ______.

a. separate variance estimator

b. pooled variance estimator

c. unequal variance estimator

d. seemingly unequal variance estimator

Learning Objective: 10.2. Explain why you must use a slightly different hypothesis test when you cannot assume the variances for two groups are equal.

Cognitive Domain: Knowledge

Answer Location: When we cannot assume equal variances: Separate variance estimate

Difficulty Level: Easy

10. The t-test provides a formal statistical test of the null hypothesis that ______.

a. two categorical variables are independent of one another

b. two means are unequal

c. two means are equal

d. one mean is larger than the other

Learning Objective: 10.4. Conduct a hypothesis test for the difference between means using the three variations of the t-test, and interpret the results.

Cognitive Domain: Knowledge

Answer Location: Testing a hypothesis about the difference between two me

Learning Objective: 10.4. Conduct a hypothesis test for the difference between means using the three variations of the t-test, and interpret the results.

Cognitive Domain: Application

Answer Location: Testing a hypothesis about the difference between two me

Learning Objective: 10.3. Describe the difference between independent groups and matched groups.

Cognitive Domain: Application

Answer Location: Matched-groups or dependent-samples test

Difficulty Level: Medium

13. If a researcher was comparing number of arrests between male and female sibling pairs, the appropriate statistical test would be ______.

a. independent t-test

b. dependent t-test

c. test of proportions

d. pooled variance estimate

Learning Objective: 10.3. Describe the difference between independent groups and matched groups.

Cognitive Domain: Application

Answer Location: Matched-groups or dependent-samples test

Difficulty Level: Medium

14. In the equations for a t-test in matched or dependent samples, , is ______.

a. the standard deviation

b. the variance

c. the mean of one group

d. the mean of the difference between each pair of scores in the sample

Learning Objective: 10.3. Describe the difference between independent groups and matched groups.

Cognitive Domain: Comprehension/Application

Answer Location: Matched-groups or dependent-samples test

Difficulty Level: Easy

True/False

15. The t-test and z-test of means is appropriate for an independent variable that has two categories and a dependent variable that is continuous.

Learning Objective: 10.4. Conduct a hypothesis test for the difference between means using the three variations of the t-test, and interpret the results.

Cognitive Domain: Knowledge

Answer Location: Explaining the difference between two sample means

Difficulty Level: Easy

16. Rarely does one know the population variance.

Learning Objective: 10.3. Describe the difference between independent groups and matched groups.

Cognitive Domain: Knowledge

Answer Location: Sampling distribution of mean differences

Difficulty Level: Easy

17. In independent random samples, both samples are randomly selected and independent of one another.

Learning Objective: 10.3. Describe the difference between independent groups and matched groups.

Cognitive Domain: Knowledge

Answer Location: Testing a hypothesis about the difference between two me

Learning Objective: 10.3. Describe the difference between independent groups and matched groups.

Cognitive Domain: Knowledge

Answer Location: Testing a hypothesis about the difference between two me

Learning Objective: 10.3. Describe the difference between independent groups and matched groups.

Cognitive Domain: Knowledge

Answer Location: Matched group or dependent-samples test

Difficulty Level: Easy

20. If the F test leads us to reject the null hypothesis we must then conclude that the two population standard deviations are the same.

Learning Objective: 10.2. Explain why you must use a slightly different hypothesis test when you cannot assume the variances for two groups are equal.

Cognitive Domain: Knowledge

Answer Location: Model 1: Pooled variance estimate; Model 2: Separate variance estimate

Difficulty Level: Hard

21. A researcher wishing to compare the values of parents and children collects data from 10 children and their parents. The t-test for dependent means would be the appropriate statistical analysis.

Learning Objective: 10.3. Describe the difference between independent groups and matched groups.

Cognitive Domain: Comprehension/Application

Answer Location: Matched-groups or dependent-samples test

Difficulty Level: Medium

22. A sample of 15 students had data collected on their reading scores before and after a literacy intervention program was implemented. The degrees of freedom for this group would be 13.

Learning Objective: 10.3. Describe the difference between independent groups and matched groups.

Cognitive Domain: Comprehension/Application

Answer Location: Matched-groups or dependent-samples test

Difficulty Level: Medium

23. When testing for a difference between proportions, a researcher would use the z-statistic instead of the t-statistic.

Learning Objective: 10.5. Conduct a hypothesis test for the difference between proportions, and interpret the results.

Cognitive Domain: Comprehension

Answer Location: Hypothesis tests for the difference between two proportions: Large samples

Difficulty Level: Medium

24. In comparing the average number of times one has driven drunk between those in Alcoholics Anonymous compared to seniors in high school, one would rely on a dependent-samples t-test.

Learning Objective: 10.3. Describe the difference between independent groups and matched groups.

Cognitive Domain: Application

Answer Location: Matched-groups or dependent-samples test

Difficulty Level: Medium

Essay

25. When is it appropriate to use the t-test for independent-samples, t-test for dependent samples, and the test for differences between two proportions?

Learning Objective: 10.4. Conduct a hypothesis test for the difference between means using the three variations of the t-test, and interpret the results.

Cognitive Domain: Application

Answer Location: Testing a hypothesis about the difference between two me