I administer the same exam to three separate sections of an

I administer the same exam to three separate sections of an Introduction to Psychology course. Mean scores for each section are reported below. Compute the weighted mean.

Section 1 (n = 10)        M = 40

Section 2 (n = 10)        M = 45

Section 3 (n = 50)        M = 70

Solution

The weighted mean is:

(40*10+45*10+70*50)/(10+10+50)

=62.14