7. Would you expect more reliable cars to cost more? Consumer Reports rated 15 upscale sedans. Reliability was rated on a 5-point scale: poor (1), fair (2), good (3), very good (4), and excellent (5). The price and reliability rating for each of the 15 cars are shown (Consumer Reports, February 2004).

a. Develop a scatter diagram for these data with the reliability rating as the independent variable.

b. Develop the least squares estimated regression equation.

c. Based upon your analysis, do you think more reliable cars cost more? Explain.

d. Estimate the price for an upscale sedan that has a good reliability rating.