John Smith, the research manager for marketing the Chevrolet Division of the General Motors Corporation, has specified the following general demand function for Chevrolets in the United states: Q_c = f(P_c, N, I, P_F, P_G, A, P_I) where Q_c is the quantity demanded of Chevrolets per year, P_c is the price of Chevrolets. N is population I is disposable income, P_F is the price of Ford automobiles, P_G is the price of gasoline, A is the amount of advertising for Chevrolets, and P_I is credit incentives to purchase Chevrolets. Indicate whether you expect each independent or explanatory variable to be directly or inversely related to the quantity demanded of Chevrolets and the reason for your expectation. Suppose that GM's Smith estimated the following regression equation for Chevrolet automobiles: Q_c = 100,000 - 100P_c + 2,000N + 50I + 30P_F - 1,000P_G + 3A + 40,000 P_I where Q_c = quantity demanded per year of Chevrolet automobiles P_c = price of Chevrolet automobiles, in dollars N = population of the United States, in millions I = per capita disposable income, in dollars P_F = price of Ford automobiles, in dollars P_G = real price of gasoline, in cents per gallon A = advertising expenditures by Chevrolet. in dollars per year P_I = credit incentives to purchase Chevrolets, in percentage points below the rate of interest on borrowing in the absence of incentives Indicate the change in the number of Chevrolets purchased per year (Q_c) for each unit change in the independent or explanatory variables. Find the value of Q_c if the average value of P_c = $9,000, N = 200 million, I = $10,000, P_F = $8,000 P_G = 80 cents, and A = $200,000, and if P_I = 1. Derive the equation for the demand curve for Chevrolets. Plot it. Starting with the estimated demand function for Chevrolets given in Problem 2, assume that the average value of the independent variables changes to N = 225 million, 1 = $12,000, P_F = $10,000.