The paired-difference t-test for the main difference between two populations assumes:

A) that the populations are approximately normally distributed
B) that the sample variances are equal
C) that the sample means are equal
D) all of these
E) none of these

Paired-Difference T-Test

A statistical method used to compare the means of two related groups to determine if there is a significant difference between them.

Normally Distributed

A type of probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean.

Sample Variances

A measure of the dispersion of a set of data points in a sample.