statistics
posted by Gregory on .
A person scores 81 on a test of verbal ability and 6.4 on a test of quantitative ability. For the verbal ability test, the mean for people in general is 50 and the standard deviation is 20. For the quantitative ability test, the mean for people in general is 0 and the standard deviation is 5. Which is this personâ€™s stronger ability: verbal or quantitative? Explain your answer to a person who has never had a course in statistics.

Start by finding the z scores.
z = (value  mean)/SD
verbal: z = (8150)/20
z = 1.55
quantitative: z = (6.40)/5
z = 1.28
Compare the z scores. 1.55 > 1.28. Therefore, the person's score exceeded the mean by more in the verbal test.