Compare the scores: a score of 220 on a test with a mean of 200 and a standard deviation of 21 and a score of 90 on a test with a mean of 80 and a standard deviation of 8.
A)A score of 90 with a mean of 80 and a standard deviation of 8 is better.
B)A score of 220 with a mean of 200 and a standard deviation of 21 is better.
C)The two scores are statistically the same.
D)You cannot determine which score is better from the given information.

Question

Quizplus · Accepted Answer

A score of 90 on a test with a mean of 80 and a standard deviation of 8 is 1.25 standard deviations above the mean (90-80)/8 = 1.25, while a score of 220 on a test with a mean of 200 and a standard deviation of 21 is only about 0.95 standard deviations above the mean (220-200)/21 = 0.95. Therefore, relative to their respective distributions, the score of 90 is better.

Compare the Scores: a Score of 220 on a Test