An automotive sales manager wishes to examine the relationship between age (years) and sales price ($) for used Honda automobiles. The file HondaPrices contains data for a sample of Honda Civic LXs that were listed for sale at a car shopping website. (Data extracted from cargurus.com.)

a. Construct a scatter plot for age and price.

b. Fit a quadratic regression model to predict price and state the quadratic regression equation.

c. Predict the mean price of a Honda Civic LX that is five years old.

d. Perform a residual analysis on the results and determine whether the regression model is valid.

e. At the 0.05 level of significance, is there a significant quadratic relationship between age and price?

f. What is the p-value in (e)? Interpret its meaning.

g. At the 0.05 level of significance, determine whether the quadratic model is a better fit than the linear model.

h. What is the p-value in (g)? Interpret its meaning.

i. Interpret the meaning of the coefficient of multiple determination.

j. Compute the adjusted r2.

k. What conclusions can you reach concerning the relationship between age and price?