To construct an interval estimate for the difference between the means of two populations when the standard deviations of the two populations are unknown, we must use a t distribution with (let n₁ be the size of sample 1 and n₂ the size of sample 2) _____ degrees of freedom. A) n₁ + n₂ B) n₁ + n₂ - 1 C) n₁ + n₂ - 2 D) n₁ - n₂ + 2

Question

Quizplus · Accepted Answer

The degrees of freedom for a t-test when estimating the difference between two means with unknown population standard deviations is calculated as the sum of the sample sizes of both groups minus 2, which corresponds to $n_1 + n_2 - 2$.

To Construct an Interval Estimate for the Difference Between the Means