Question
Mrs. Gifford's class consists of 15 girls and 25 boys.
On the first test the mean of the girls’ scores was 80 and the mean of the boy’s scores was 70. What was the class mean? (Remember the class mean is not just averaging the two means)
On the first test the mean of the girls’ scores was 80 and the mean of the boy’s scores was 70. What was the class mean? (Remember the class mean is not just averaging the two means)
Answers
PsyDAG
mean = ∑x/n
Girl's 80 = ∑x/15
x = 1200
Boy's 70 = ∑x/25
x = 1750
Class mean = (1200+1750)/(15+25) = ?
Girl's 80 = ∑x/15
x = 1200
Boy's 70 = ∑x/25
x = 1750
Class mean = (1200+1750)/(15+25) = ?
Damon
(80*15 + 70*25)/(40)