Question

In an all boys school, the heights of the student body are normally distributed with a mean of 68 inches and a standard deviation of 3 inches. Using the empirical rule, what percentage of the boys are between 62 and 74 inches tall?

Answer 1

62 and 74 are 68 ± 2σ (since (62−68)/3 = −2 and (74−68)/3 = +2). By the empirical rule about 95% of the boys fall within ±2 standard deviations, so approximately 95%.