The difference between means is 4. The pooled variance is 9. What is the value of Cohen's d for an independent samples t test?
A) 2.25
B) .44
C) .75
D) 1.33

Question

Quizplus · Accepted Answer

Cohen's d formula for an independent samples t test is:
d = (X1 - X2) / sqrt(sp^2)
where X1 - X2 is the difference between means, sqrt is the square root, and sp^2 is the pooled variance.
 
Substituting the given values:
d = 4 / sqrt(9)
d = 4 / 3
d = 1.33
 
Therefore, the answer is D.

The Difference Between Means Is 4