13)Which of the following would be the only reason to eliminate explanatory variables ? a)Nonlinearity

b) Multicollinearity

c)Sign switch

d)Autocorrelation T

e)here is never any good reason to eliminate information.

15)Which of the following is NOT an assumption of multiple regression models ?

a) All Xs should be measured should be continuous scale ; they can't be discrete .

b)A linear relationship exists between each X variable and Y.

c)The error terms should be independent of each other .

d)X variables should not be very highly correlated with each

16)Which one is NOT correct regarding the error term?

a)ERROR = y - yhat

b)If ERRORS are random model is adequate .

c)ERROR is what is left over after we model .

d)Every error term should be 0 .

17)Given the following information : YHAT = 32 + 15X

Which of the following may NOT be true?

a)This is the least squares fitted line for a simple regression .

b) If x = 3 then yhat = 77 .

c) X is a significant variable .

d)We can forecast values of Y for any X.