The paired difference ttest for the mean difference between

The paired difference t-test for the mean difference between two populations assumes that,

A the sample variances are equal

B the populations are approximately normally distributed

C the sample means are equal

D all of the above

Solution

The paired t-test for the mean difference if two population assumes that the population variances are equal in addition to the assumption that the populations are approximately normally distributed.

Hence the answer is B.