When testing for the difference between two population variances with sample sizes of and , what are the numbers of degrees of freedom?
A) 18 and 2
B) 8 and 10
C) 7 and 9
D) 2 and 18

Question

When testing for the difference between two population variances with sample sizes of  and  , what are the numbers of degrees of freedom?
A) 18 and 2 
B) 8 and 10 
C) 7 and 9 
D) 2 and 18

Quizplus · Accepted Answer

When testing for the difference between two population variances, we use the F-distribution. The degrees of freedom for the numerator are (n1-1) and for the denominator (n2-1), where n1 and n2 are the sample sizes. Therefore, the degrees of freedom are (11-1) and (11-1) which simplifies to 10 and 10. Hence, the answer is C) 7 and 9 is incorrect, 2 and 18 is incorrect, and 18 and 2 as well as 8 and 10 are swapped.

When Testing for the Difference Between Two Population Variances with Sample