If the variances of the two populations are not equal, it is appropriate to use the "pooled" formula to determine the t-statistic for the hypothesis test of the difference in the two population means.

Question

Quizplus · Accepted Answer

The "pooled" formula for the t-statistic assumes that the variances of the two populations are equal. When the variances are not equal, an alternative approach, such as Welch's t-test, should be used.

If the Variances of the Two Populations Are Not Equal