If we are testing for the difference between the means of 2 independent populations presuming equal variances with samples of $n _ { 1 } = 20 \text { and } n _ { 2 } = 20$ , the number of degrees of freedom is equal to
A) 39.
B) 38.
C) 19.
D) 18.

Question

Quizplus · Accepted Answer

When testing for the difference between the means of two independent populations with equal variances, the degrees of freedom is calculated as $ n_1 + n_2 - 2 $. Here, $ n_1 = 20 $ and $ n_2 = 20 $, so the degrees of freedom is $ 20 + 20 - 2 = 38 $.

If We Are Testing for the Difference Between the Means n1=20 and n2=20n _ { 1 } = 20 \text { and } n _ { 2 } = 20n1​=20 and n2​=20

If We Are Testing for the Difference Between the Means $n _ { 1 } = 20 \text { and } n _ { 2 } = 20$