Question

On a standardized exam, the scores are normally distributed with a mean of 185 and a standard deviation of 10. Find the z-score of a person who scored 170 on the exam

Answer 1

z = (170 − 185) / 10 = −15 / 10 = −1.5.

So the score is 1.5 standard deviations below the mean (about the 6.7th percentile).