The variance of a distribution of differences between means equals:
A)the difference between the variances of the two distributions of means
B)the sum of the variances of the two distributions of means
C)the difference between the two estimated population variances
D)the sum of the two estimated population standard deviations

Question

Quizplus · Accepted Answer

The variance of the distribution of differences between means is calculated by adding the variances of the two distributions of means. This is because when independent random variables are subtracted (or added), their variances are summed, not their standard deviations or the differences of their variances.

The Variance of a Distribution of Differences Between Means Equals