On her first test in algebra, Mary earned a score of 75, and she made an 85 on her first psychology test. If the average score on the algebra test was a 68, with s=7, and the average on the psychology test was 91, with s=6, is Mary doing better in psychology or algebra. Why?

Answer 1

Z = (score-mean)/SD

Compute both Z scores.

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to the Z scores. Compare proportions.