Assuming the population variances are known, the population variance of the difference between two sample means is
A) the sum of the two means.
B) the sum of the variances for each population.
C) the sum of the standard deviations for each population.
D) the sum of the sample sizes for each population.

Question

Quizplus · Accepted Answer

The variance of the difference between two sample means is equal to the sum of the variances of each population. This can be derived from the formula for the variance of the difference between two random variables. Therefore, choice B is the best choice.

Assuming the Population Variances Are Known, the Population Variance of the Difference