The distribution of hours of sleep per school night, among high school seniors, is found to be Normally distributed, with a mean of 6.6 hours and a standard deviation of 1.3 hours. Use this information and the 68-95-99.7 rule to answer the following questions. What percentage of high school seniors sleep more than 7.9 hours? Less than 4 hours? What range contains the middle 68% of hours slept per weeknight by high school seniors