# Statistics: Statistical Hypothesis Testing and Easy Keywords

Pages: 39 (6986 words) Published: August 31, 2013
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 DIFFICULTY: Moderate
KEYWORDS: t test for mean difference

6. In testing for the differences between the means of 2 independent populations, where the variances in each population are unknown but assumed equal, the degrees of freedom are a) n – 1.

b) n1 + n2 – 1.
c) n1 + n2 – 2.
d) n – 2.

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

7. In testing for differences between the means of 2 related populations, where the variance of the differences is unknown, the degrees of freedom are a) n – 1.
b) n1 + n2 – 1.
c) n1 + n2 – 2.
d) n – 2.

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

8. In testing for differences between the means of two related populations, the null hypothesis is a) [pic].
b) [pic].
c) [pic].
d) [pic].

ANSWER:
b
TYPE: MC DIFFICULTY: Easy
KEYWORDS: t test for mean difference, form of hypothesis

9. In testing for differences between the means of two independent populations, the null hypothesis is: a) [pic] = 2.
b) [pic] = 0.
c) [pic] > 0.
d) [pic] < 2.

ANSWER:
b
TYPE: MC DIFFICULTY: Easy
KEYWORDS: pooled-variance t test, form of hypothesis

10. In testing for differences between the median of two independent populations, the null hypothesis is a) [pic].
b) [pic].
c) [pic].
d) [pic].

ANSWER:
c
TYPE: MC DIFFICULTY: Easy
KEYWORDS: Wilcoxon rank sum test, form of hypothesis

11. In testing for whether the median difference of two related populations is zero, the null hypothesis is a) [pic].
b) [pic].
c) [pic].
d) [pic].

ANSWER:
a
TYPE: MC DIFFICULTY: Easy
KEYWORDS: Wilcoxon rank sum test, form of hypothesis

12. When...

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