QUESTION 4 [25] The following model relates the quantity demanded of a commodity (Y) to the price of the commodity (X2) and consumer income (X3): Y. = B1 + B2Xzt + B3Xat + Ht Data for the 15 year period from 1990 to 2004 was used to estimate the model, yielding the regression equation: Y, = 82.2666 - 5.1061X2 + 0.0167X3t (1.4146) (0.0065) a. Clearly interpret the estimated parameters B2 and B3. [6] b. Test the individual significance of the slope parameter B2. (a = 5%) c. Test the overall significance of the regression (using the F-test, a = 5%) [6] d. If R2 = 0.9508, calculate the adjusted R and comment on the results. Why is it necessary to adjust [7]