13.22 Use the data in the file Citydatr to estimate a regression equation that can be used to determine the marginal effect of the percent commercial property on the market value per owner-occupied residence

(Hseval). Include the percent of owner-occupied residences

(Homper), percent of industrial property (Indper), the median rooms per residence (sizehse), and per capita income (Incom 72) as additional predictor variables in your multiple regression equation. The variables are described in the Chapter 12 appendix. Indicate which of the variables are conditionally significant.

Your final equation should include only significant variables. Run a second regression with median rooms per residence excluded. Interpret the new coefficient for percent commercial property that results from the second regression.

Compare the two coefficients.