Chapter 9

Question 1

What is the minimum level of measurement for t-tests?

Answer 1

Interval

Question 2

When would you use the one-sample-Z-test instead of the one-sample-t-test?

Answer 2

(a) it’s only for when you want to compare a single sample’s mean to a population mean and (b) you have to know the population standard deviation.

Question 3

When would you use the one-sample-t-test instead of the one-sample-Z-test?

Answer 3

When you want to know the sample mean to a population mean BUT you do not have the population standard deviation, so you use the sample standard deviation.

Question 4

When would you use the two-sample t-test?

Answer 4

This is used when you want to compare the means of people in two separate groups such as men and women or Republicans and Democrats. Good for experiments.

Question 5

When would you use the repeated-measures t-test?

Answer 5

This is used when you gather data from people at two points in time, such as the beginning and end of a college course, and you want to look for changes in each person’s score

Question 6

What does Cohen’s D mean for the one-sample t test?

Answer 6

to know exactly how far away the sample mean is in a generalized way

Question 7

What does Cohen’s D mean for the repeated t test?

Answer 7

to know exactly how far away the sample mean is in a generalized way

Question 8

What does Cohen’s D mean for the two sample t test?

Answer 8

to know exactly how far away the sample mean is in a generalized way

Question 9

If we were to retain (fail to reject) the null hypothesis. What is the probability of getting a Type I error? And why?

Answer 9

there would be zero risk or zero probability of a Type I error or false positive BECAUSE WE DO NOT HAVE A POSITIVE RESULT

Question 10

If we were to reject the null hypothesis. What is the probability of getting a Type II error? And why?

Answer 10

there is zero risk or zero probability of a Type II error or false negative. BECAUSE WE DO NOT HAVE A NEGATIVE RESULT

Question 11

If we were to reject the null hypothesis. What is the probability of getting a Type I error?

Answer 11

There would be a chance of a type 1 error

Question 12

If we were to retain (fail to reject) the null hypothesis. What is the probability of getting a Type II error?

Answer 12

There would be a chance of a type II error