Which of the following is NOT a required assumption for constructing a confidence interval to estimate the difference between two population means when the sample sizes are small (less than 30)?
A) The samples are randomly selected from the population.
B) The population variances are equal to 1.
C) The population variances are equal.
D) The two populations are normally distributed.

Question

Quizplus · Accepted Answer

The assumption that population variances are equal to 1 is not required for constructing a confidence interval to estimate the difference between two population means when the sample sizes are small. Instead, the assumption is that the population variances are equal. The other three assumptions (randomly selected samples, normal distribution of populations, and independent samples) are required.

Which of the Following Is NOT a Required Assumption for Constructing