A study of emergency service facilities investigated the relationship between the number of facilities and the average distance traveled to provide the emergency service. The following table gives the data collected.
Number of Facilities...................Average Distance (miles)
9..................................................................1.66
11.................................................................1.12
16....................................................................83
21...................................................................62
27...................................................................51
30...................................................................47
a. Develop a scatter diagram for these data, treating average distance traveled as the dependent variable.
b. Does a simple linear model appear to be appropriate? Explain.
c. Develop an estimated multiple regression equation for the data of the form = b0 + b1x + b1 x2.