The utility bills (in dollars) for homes is estimated by a multiple regression equation using the independent variables X1 (the number of occupants) and X2 (the number of rooms) in the home. The regression equation is given below: ^y = 300 + 7 X1 + 13 X2 a. Identify the y- intercept and the partial slopes of this model. b. Interpret the meaning of they-intercept and the partial slopes with reference to the context. c. What is the predicted bill for a family of 5 that lives in a 6-room home? According to the data, the bill was $399.00. What is the residual? d. Another researcher used a different number of variables and tried to predict a more reliable model. In the analysis he noticed that a couple of partial regression coefficients exhibited the wrong sign. What potential problem does this indicator suggest? Explain the problem. e. What is stepwise regression, and when is it desirable to make use of this particular multiple regression technique? f. Data from a different study indicated that the SS Residual (SS Error) is 150. If the researcher had fitted a regression equation model with 25 observations and had used 6 independent variables, what is the standard error of the estimate (model standard deviation)? What is the relevance of this measure in statistical analysis