The z test for independent groups is almost never used because it requires that _________ be known. A) µ ₁ C) s ₂ D) s ₂.

Question

Quizplus · Accepted Answer

The z test for independent groups requires knowledge of the standard deviation for both groups. However, in practice, the standard deviation is often unknown and must be estimated from the sample, making the t-test for independent groups a more appropriate choice.

The Z Test for Independent Groups Is Almost Never Used