Two accounting professors decided to compare the variance of their grading procedures. To accomplish this, they each graded the same 10 exams with the following results: What are the degrees of freedom for the numerator of the F ratio?
A) 8
B) 9
C) 10
D) 18

Question

Two accounting professors decided to compare the variance of their grading procedures. To accomplish this, they each graded the same 10 exams with the following results:  What are the degrees of freedom for the numerator of the F ratio?
A) 8 
B) 9 
C) 10 
D) 18

Quizplus · Accepted Answer

The degrees of freedom for the numerator of the F ratio is equal to the number of groups being compared minus 1. In this case, there are two groups (the grading procedures of the two professors) so the degrees of freedom for the numerator is 2-1=1. The degrees of freedom for the denominator is the total sample size minus the number of groups, or 10-2=8. Therefore, the F ratio has 1 and 8 degrees of freedom, making the best choice B.

Two Accounting Professors Decided to Compare the Variance of Their