The following estimated equation was developed for a model i

The following estimated equation was developed for a model involving two independent variables y = 40.7 + 8.63x1 + 2.71x2 After x2 has dropped from The model, The least squares method has used to an estimated regression equation involving Y X, as an independent variable. y = 42.0 + 9.01x1 give an interpretation of the coefficient of x, in both models. Could explain coefficient of x different in the two models? If so, how?

Solution

in the first equation

for each value of x1 in the model, Y will be increase by 8.63 , if x2 = constant

in the second equation

for each value of x1 in the model, Y will be increase by 9.01

b)

yes, could be, because X2 has values that can affect the final model , and that will be affect proportional X1