# F-test to Compare Variances

3 Questions

QUESTION 1 of 3

Hello professor, for homework 9.10 numbers 42 and 45 aren't fractions. How do I know which d.f to look up in the top row and which to look up in the left column. Both problems have the same exact claim yet in number 42, n2 is on the top row and n1 is on the left column...but number 45 is the opposite, n1 is on the top and n2 is on the left. I don't understand this because the claims for both problems are identical. Thanks.

QUESTION 2 of 3

Hi professor,

I'm stuck on HW 9.10 on problem 4.2.

The F-Test is S1 = 128 n1 = 23 and s2=162 n2=16. Where the claim is not equal. (o1^2 not equal to o2^2). The CL = 0.02, but since its a two tail test its divided by 2 ~ x= 0.01. I ended up getting: F0.01.22.15 ~> 3.372. Your answer is 2.98. To sum this up, I'm really confused. If you could help me, thank you very much.

QUESTION 3 of 3

Hello Professor,

This is Kendrick .....working on Sec't 9.10 using F-Table to find critical values, do we use d.f. for both small and large sample data ?