Chapter 9.4, Problem 66E

To determine

To calculate: The percentage of states by the empirical rule and compare it with the actual percentage of states with an aging population within one standard deviation of the mean for the year $1990$ where the list showing the percentage of the aging population (residents of age $65$ and older) in $50$ states for the year $1990$ is as follows:

$1990:$

$\begin{array}{c}4,9,10,10,10,10,10,11,11,11,11,11,11,\\ 11,11,12,12,12,12,12,12,13,13,13,13,13,\\ 13,13,13,13,13,13,13,13,13,14,14,14,14,\\ 14,14,14,14,15,15,15,15,15,15,18\end{array}$