# Thread: How many degrees of freedom

1. ## How many degrees of freedom

A two-sample test with n1=5 and n2=6 would have how many degrees of freedom for the critical value assuming normality
a. 9
b. 10
c. 11
d. None of the above

A independent two-sample test with n1=34 and n2=42 would have how many degrees of freedom for the critical value?
a. 34
b. 72
c. 74
d. None of the above

A statistical test involves a "before and after" focus with 12 subjects has how many degrees of freedom?
a. 11
b. 12
c. 24
d. None of the above

df = n1+ n2 - 2

Is this used for every one or is there a different formula to use? The only other formula I have is for t-test for unequal variances.
Also how do you now if you have unequal variances or equal variances when looking at problems?

2. ## Re: How many degrees of freedom

Originally Posted by bustacap09
Is this used for every one or is there a different formula to use? The only other formula I have is for t-test for unequal variances.
Also how do you now if you have unequal variances or equal variances when looking at problems?
It is used in every one of the questions.
You can deduce if they have equal variances by the nature of them problem. If you have a fair dice with sides 1-6 and a fair dice with sides 7-12 then you know their variances are equal. Usually you wont be able to deduce that their variances are equal.