Question

When Hailey commutes to work, the amount of time it takes her to arrive is normally distributed with a mean of 59 minutes and a standard deviation of 2 minutes. Using the empirical rule, what percentage of her commutes will be between 53 and 65 minutes?

Answer 1

53 and 65 minutes are 3 standard deviations from the mean (59 ± 3·2). By the empirical rule about 99.7% of values lie within ±3σ, so approximately 99.7% of her commutes.