Use the Empirilll Rule. The mean speed of a sample of vehicles along .9. stretch of highway is 65 miles per hour, with a standard deviation of 4 miles per hour. Estimate the percent of vehicles whose speeds are between 53 miles per hour and T"? miles per hour. [Assume the data set has a bellshaped distribution.) Approximately CI?! of vehicles travel between 53 miles per hour and 77 miles per hour