Use the Empirical Rule. The mean speed of a sample of vehicles along a stretch of highway is 64 miles perhour, with a standard deviation of 5 miles per hour. Estimate the percent of vehicles whose speeds are between 54 miles per hour and 74 miles per hour.(Assume the data set has abell-shaped distribution.)

Approximately

nothing

% of vehicles travel between 54 miles per hour and 74 miles per hour.