According to data for a​ population, 3-year-old boys have a mean height of 38 inches and a standard deviation of 2 inches. Assume the distribution is approximately Normal.  Find the percentile measure for a height of 42 inches for a​ 3-year-old boy.

Use the Empirical Rule. The mean speed of a sample of vehicles along a stretch of highway is 70 miles per hour, with a standard deviation of 4 miles per hour. Estimate the percent of vehicles whose speeds are between 62 miles per hour and 78 miles per hour. (Assume the data set has a bell-shaped distribution.) Approximately% of vehicles travel between 62 miles per hour and 78 miles per hour.

Use the Empirical Rule. The mean speed of a sample of vehicles along a stretch of highway is 67 miles per hour, with a standard deviation of 5 miles per hour. Estimate the percent of vehicles whose speeds are between 52 miles per hour and 82 miles per hour. (Assume the data set has a bell-shaped distribution.) Approximately % of vehicles travel between 52 miles per hour and 82 miles per hour.

The data in a data set are normally distributed with a mean of 190 and a standard deviation of 30. Estimate the percent of the data that are less than 130 or greater than 250.