How fast can male college students run a mile? There's lots of variation, of course. During World War II, physical training was required for male students in many colleges, as preparation for military service. That provided an opportunity to collect data on physical performance on a large scale. A study of 12,000 able-bodied male students at the University of Illinois found that their times for the mile run were approximately Normal with mean 7.06 minutes and standard deviation 0.7 minute.

It's good practice to draw a Normal curve on which this mean and standard deviation are correctly located. To do this, draw an unlabeled Normal curve, locate the points where the curvature changes (this is 1 standard deviation from the mean), then add number labels on the horizontal axis.

Use the Empirical Rule to answer the following questions.

1. What range of times covers the middle99.7%of this distribution? From to minutes Round to 2 places.
2. What percent of these runners run the mile between 6.36 and 9.16 minutes? % Round to 2 places.
3. What percentage of the these running times are longer than 5.66 minutes? % Round to 2 places.