The exercise involving data in this and subsequent sections were designed to be solved using excel.
the following estimated regression equation was developed for a model involving two independent variables.
y hat = 40.7 + 8.63x1 +2.71x2
after x2 was dropped from the model, the least squares method was used to obtain an estimated regression equation involving only x1 as an independent variable.
y hat = 42.0 + 9.01x1
a. in the two independent variable case, the coefficient x1 represents the expected change in - select your answer -yx1x2item 1corresponding to a one unit increase in - select your answer -yx1x2item 2 when - select your answer -yx1x2item 3 is held constant.
in the single independent variable case, the coefficient x1 represents the expected change in - select your answer -yx1x2item 4corresponding to a one unit increase in - select your answer -yx1x2item 5 .
b. could multicollinearity explain why the coefficient of x1 differs in the two models? assume that x1 and x2 are correlated.
- select your answer -yes, because a change in x1 would be accompanied by a change in x2yes, because a change in x1 would not be accompanied by a change in x2