Given the information: , , , , how many degrees of freedom should be used in the pooled variance t test?
A) 40
B) 38
C) 25
D) 15

Question

Given the information:  ,  ,  ,  , how many degrees of freedom should be used in the pooled variance t test?
A) 40 
B) 38 
C) 25 
D) 15

Quizplus · Accepted Answer

To calculate the degrees of freedom for a pooled variance t test, we use the formula:

df = (n1 - 1) + (n2 - 1)

where n1 and n2 are the sample sizes for the two groups being compared.

In this case, we have four groups, each with the same sample size of 11. To calculate the degrees of freedom for a pooled variance t test comparing all four groups, we need to combine the sample sizes for the first two groups and the sample sizes for the last two groups. This gives us:

df = (11 - 1) + (11 - 1) + (11 - 1) + (11 - 1) = 38

Therefore, the correct answer is B) 38.

Given the Information: ,