Use the Empirical Rule, The mean speed of a sample of vehicles along a stretch of highway is 68 miles per hour, with a standard deviation of 4 miles per hour. Estimate the percent of vehicles whose...

Use the emperical rule. Please solve that problem

Extracted text: Use the Empirical Rule, The mean speed of a sample of vehicles along a stretch of highway is 68 miles per hour, with a standard deviation of 4 miles per hour. Estimate the percent of vehicles whose speeds are between 56 miles per hour and 80 miles per hour. (Assume the data set has a bell-shaped distribution.) Approximately % of vehicles travel between 56 miles per hour and 80 miles per hour.