A random sample of data was collected on residential sales in a large city. The accompanying table shows the selling price (Y, in $ 1,000s), area (X1, in hundreds of square feet), number of bedrooms (X2), total number of rooms (X3), house age (X4, in years), and location (Z = 0 for in-town and inner suburbs, Z = 1 for outer suburbs).
In parts (a) through (c), use variables X1, X2, X3, X4, and Z as the predictor variables. Use the accompanying computer output to answer parts (a)-(d).
a. Use the all possible regressions procedure to suggest a best model.
b. Use the stepwise regression algorithm to suggest a best model.
c. Use the backward-elimination algorithm to suggest a best model.
d. Which of the models selected in parts (a), (b), and (c) seems to be the best model, and why?

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