The article referenced in the previous exercise also gave data on the percentage of operating costs covered by park revenues for the 2007–2008 fiscal year.

Number of Employees, x Percent of Operating Cost Covered by Park Revenues, y 95 37 95 19 102 32 69 80 67 17 77 34 81 36 116 32 51 38 36 40 Number of Employees, x Percent of Operating Cost Covered by Park Revenues, y 96 53 71 31 76 35 112 108 43 34 87 97 131 62 138 36 80 36 52 34

a. Find the equation of the least-squares line relating y 5 percent of operating costs covered by park revenues and x 5 number of employees.

b. Based on the values of r 2 and se, do you think that the least-squares regression line does a good job of describing the relationship between y 5 percent of operating costs covered by park revenues and x 5 number of employees? Explain.

c. The graph in Figure EX5.40 is a scatterplot of y 5 percent of operating costs covered by park revenues and x 5 number of employees. The least-squares line is also shown. Which observations are outliers? Do the observations with the largest residuals correspond to the park districts with the largest number of employees?