A researcher working in a Human Resources department was interested in gender and sales figures so he conducted a t-test. The mean for males was 66.25 and the mean for females was 78.24, with both groups having a standard deviation of 7. What is the effect size using Cohen's d?
A)1.712
B)0
C)1.7
D)-1.712

Question

Quizplus · Accepted Answer

Cohen's d formula: 
d = (M1 - M2) / S
Where M1 and M2 are the means of Group 1 and Group 2, respectively, and S is the pooled standard deviation. 
Using this formula, we can calculate:
d = (78.24 - 66.25) / 7
d = 1.714
The effect size using Cohen's d is 1.712 (rounded to three decimal places), which indicates a large effect size according to Cohen's guidelines. Therefore, the best answer is A.

A Researcher Working in a Human Resources Department Was Interested