WhereY=imports (number of cars imported),X1=Gross National Product (GNP) in Kwacha,=price of imported goods,t=time in years and values in the parentheses are standard errors. 

a. Interpret all the partial regression coefficients in the estimated model above. 

 

Using observations for a period 1990 to 2020, RM estimated the import function for cars in Zambia and obtained the following estimated import function: InY= 10 + 9.1lnX -0.34X2 -0.03t (-4.4) (0.01) se (2.2) (5.5) R = 0.9