When performing a hypothesis test for the difference between the means of two independent populations, where the standard deviations are known, the variances must be assumed equal.

Question

Quizplus · Accepted Answer

When performing a hypothesis test for the difference between the means of two independent populations with known standard deviations, it is not necessary to assume equal variances; one can use the z-test formula that incorporates the standard deviations of both populations directly without assuming equal variances.

When Performing a Hypothesis Test for the Difference Between the Means