why-is-it-important-that-the-two-samples-in-a-two-sample-t-test-are-independent

Question

Why is it important that the two samples in a two-sample t-test are independent?

Accepted Answer

Because dependence between samples can bias the estimate of the difference in means.

Answer

Because independence is only required for one-sample tests.

Answer

Because independence is not an important assumption.

Answer

Because independence ensures the variances are equal.