Assume that a set of test scores in an Introduction to Finance class is normally distributed with a mean of 72 and a standard deviation of 8. Use the 68-95-99.7 rule to
Find the percentage of scores less than 56.
A) 0.15%
B) 0.3%
C) 2.5%
D) 5%
E) 95%

Question

Quizplus · Accepted Answer

56 is two standard deviations below the mean (72 - 2*8 = 56). According to the 68-95-99.7 rule, 95% of scores are within two standard deviations of the mean, leaving 5% outside. Since the distribution is symmetric, 2.5% of scores are below 56.

Assume That a Set of Test Scores in an Introduction