What assumption is made so that the pooled variance estimate can be substituted for the population variances within the standard error of the differences formula?
A)the population variances are homogeneous.
B)the population variances are heterogeneous.
C)the sample sizes are equal.
D)the sample sizes are large.

Question

Quizplus · Accepted Answer

Pooled variance estimate can be substituted for the population variances within the standard error of the differences formula when the population variances are assumed to be homogeneous. This means that the variances of the populations from which the samples are drawn are assumed to be equal. In such cases, the pooled variance estimate is a weighted average of the sample variances that tends to give a more accurate estimate of the population variance than the individual sample variances.

What Assumption Is Made So That the Pooled Variance Estimate