Use the Empirical Rule. The mean speed of a sample of vehicles along a stretch of highway is 69 miles per​ hour, with a standard deviation of 3 miles per hour. Estimate the percent of vehicles whose...

Use the Empirical Rule. The mean speed of a sample of vehicles along a stretch of highway is 69 miles per​ hour, with a standard deviation of 3 miles per hour. Estimate the percent of vehicles whose speeds are between 63 miles per hour and 75  miles per hour.​ (Assume the data set has a​ bell-shaped distribution.)

Approximately ___% of vehicles travel between 63 miles per hour and 75 miles per hour.