Deck 8: The Single-Sample T Test

Question 1

Which of the following refers to the set of distributions that, although symmetrical and bell-shaped, are not normally distributed?

A) Student's t distribution
B) Gosset's t distribution
C) The z distribution
D) None of the above

Answer 1

Student's t distribution

Question 2

Calculate the degrees of freedom for a single-sample t test with 10 subjects.

A) 10
B) 9
C) 8
D) Cannot be determined

Answer 2

9

Question 3

Calculate the degrees of freedom for a single-sample t test with 12 subjects.

A) 10
B) 11
C) 12
D) Cannot be determined

Answer 3

11

Question 4

Calculate the degrees of freedom for a single-sample t test with 18 subjects.

A) 17
B) 18
C) 16
D) Cannot be determined

Question 5

In a study with 25 subjects and s = 15, the estimated standard error of the mean would be:

A) 0.6.
B) 3.0.
C) 2.0.
D) 2.6.

Question 6

In a study with 16 subjects and s = 10, the estimated standard error of the mean would be:

A) 1.0.
B) 1.5.
C) 2.0.
D) 2.5.

Question 7

Assume that the average person in America weighs 150 pounds ( $\mu$ ). You want to determine whether college students weigh less than the average American. Following are the weights collected on a sample of college students: 120, 105, 166, 170, 145, 149, 135, 115, 168, 138.

-Is this a one- or two-tailed test?

Question 8

Assume that the average person in America weighs 150 pounds ( $\mu$ ). You want to determine whether college students weigh less than the average American. Following are the weights collected on a sample of college students: 120, 105, 166, 170, 145, 149, 135, 115, 168, 138.

-What are H₀ and H_a for this study?

Question 9

Assume that the average person in America weighs 150 pounds ( $\mu$ ). You want to determine whether college students weigh less than the average American. Following are the weights collected on a sample of college students: 120, 105, 166, 170, 145, 149, 135, 115, 168, 138.

-Compute tobt.

Question 10

Assume that the average person in America weighs 150 pounds ( $\mu$ ). You want to determine whether college students weigh less than the average American. Following are the weights collected on a sample of college students: 120, 105, 166, 170, 145, 149, 135, 115, 168, 138.

-What is tcv?

Question 11

Assume that the average person in America weighs 150 pounds ( $\mu$ ). You want to determine whether college students weigh less than the average American. Following are the weights collected on a sample of college students: 120, 105, 166, 170, 145, 149, 135, 115, 168, 138.

-Should H_o be rejected? What should the researcher conclude?

Question 12

Assume that the average person in America weighs 150 pounds ( $\mu$ ). You want to determine whether college students weigh less than the average American. Following are the weights collected on a sample of college students: 120, 105, 166, 170, 145, 149, 135, 115, 168, 138.

-Calculate the 95% confidence interval.

Question 13

How does a t test differ from a z test in terms of when it is used, how it is calculated, and how the significance is determined?

Question 14

Rich performed a two-tailed test for an experiment in which N = 20. He could not find his t critical values table, but he remembered that the t_cv at df = 15. He decided to compare his t_obt to this t_cv. Is he more likely to make a Type I or a Type II error in this situation?

Question 15

Aura performed a two-tailed test for an experiment in which N = 15. She could not find her t critical values table, but she remembered that the t_cv at df = 20. She decided to compare her t_obt to this t_cv. Is she more likely to make a Type I or a Type II error in this situation?