A national tutoring service is experimenting with two differ

A national tutoring service is experimenting with two different methods for teaching students statistics. Method A uses Google computers and Method B uses TI calculators. Random samples of students are assigned to Method A and Method B. The increase in grades from previous exams is then calculated. The results are presented in the table. A researcher is interested in determining whether there is evidence that the two methods yield different average grade increases.

Method A

Method B

Sample Mean of Grade Increase

3.0

4.0

Sample Sums of Squares

11

3.25

Sample Size

12

14

What type of t test should she carry out?

Solution

This is 2 sample t test because there are clearly 2 samples independent of each other, and we are comparing their means.