The results of a mathematics placement exam for samples of 2

The results of a mathematics placement exam for samples of 2013 and 2014 entering freshmen are as follows:

Class

Sample Size

Mean

Sample SD

2013

330

33

8

2014

310

31

7

22. What is the size of the difference between the average exam scores of freshmen in the two years?

Solution

Difference is 33 - 31 = 2