Statistics: Statistical Hypothesis Testing and Easy Keywords

CHAPTER 10: TWO-SAMPLE TESTS
WITH NUMERICAL DATA

1. The t test for the difference between the means of 2 independent populations assumes that the respective a) sample sizes are equal. b) sample variances are equal. c) populations are approximately normal. d) all of the above

ANSWER: c TYPE: MC DIFFICULTY: Moderate KEYWORDS: pooled-variance t test, assumption

2. The t test for the mean difference between 2 related populations assumes that the respective a) population sizes are equal. b) sample variances are equal. c) populations are approximately normal or sample sizes are large enough. d) all of the above

ANSWER: c TYPE: MC DIFFICULTY: Moderate KEYWORDS: t test for mean difference, assumption

3. If we are testing for the difference between the means of 2 related populations with samples of n1 = 20 and n2 = 20, the number of degrees of freedom is equal to a) 39. b) 38. c) 19. d) 18.

ANSWER: c TYPE: MC DIFFICULTY: Easy KEYWORDS: t test for mean difference, degrees of freedom

4. If we are testing for the difference between the means of 2 independent populations with samples of n1 = 20 and n2 = 20, the number of degrees of freedom is equal to a) 39. b) 38. c) 19. d) 18.

ANSWER: b TYPE: MC DIFFICULTY: Easy KEYWORDS: pooled-variance t test, degrees of freedom

5. In what type of test is the variable of interest the difference between the values of the observations rather than the observations themselves? a) a test for the equality of variances from 2 independent populations b) a test for the difference between the means of 2 related populations c) a test for the difference between the means of 2 independent populations d) all of the above

ANSWER: b TYPE: MC