When estimating a confidence interval for the difference between 2 means using the method where sample variances are pooled, which of the following assumptions is not needed?
A) The populations are normally distributed.
B) The populations have equal variances.
C) The samples are independent.
D) The sample sizes are equal.

Question

Quizplus · Accepted Answer

The assumption that the sample sizes must be equal is not needed when estimating a confidence interval for the difference between two means using the pooled variance method. The method requires the assumption of equal variances (B) but can accommodate unequal sample sizes.

When Estimating a Confidence Interval for the Difference Between 2