Chapter 5, Problem 15CR

The following data represent the percent of all drivers by age who have been stopped by the policy for any reason within the past year. The median age represents the midpoint of the upper and lower limit for the age range.

$\begin{array}{ccc}\text{Age}\text{Range}& \text{Median}\text{Age,}\text{x}& \text{Percentage}\text{Stopped, y}\\ 16-19& 17.5& 18.2\\ 20-29& 24.5& 16.8\\ 30-39& 34.5& 11.3\\ 40-49& 44.5& 9.4\\ 50-59& 54.5& 7.7\\ \ge 60& 69.5& 3.8\end{array}$

Using a graphing utility, draw a scatter plot of the data treating median age, $x$, as the independent variable.

Determine a model that best describes the relation between median age and percent stopped. You may choose from among linear, quadratic, cubic, exponential, logarithmic, and logistic models.

Provide a justification for the model that you selected in part (b).