In a normal distribution, the empirical rule tells us that 99.7% of the data falls within 3 standard deviations from the mean. This means up to 3 below and up to 3 above.
Each standard deviation is 4.5 inches; this makes 3 standard deviations
3(4.5) = 13.5 inches
This means 3 standard deviations below the mean will be
60-13.5 = 46.5 inches.
This means that 3 standard deviations above the mean will be 60+13.5 = 73.5 inches.
