Classified ads in a newspaper offered several used Toyota Corollas for sale. Listed below are the ages of the cars and the advertised prices.
Age (yr) Prices Advertised ($)
1 ........ 13990
1 ........ 13495
3 ........ 12999
4 ........ 9500
4 ........ 10495
5 ........ 8995
5 ........ 9495
6 ........ 6999
7 ........ 6950
7 ........ 7850
8 ........ 6999
8 ........ 5995
10 ........ 4950
10 ........ 4495
13 ........ 2850
a) Make a scatterplot for these data.
b) Do you think a linear model is appropriate? Explain.
c) Find the equation of the regression line.
d) Check the residuals to see if the conditions for inference are met.