Discuss the following statements and explain why they are true or false:
a) Increasing the number of predictor variables will never decrease the R^2.
b) Multicollinearity affects the interpretation of the regression coefficients.
c) The variance inflation factor of Bhat depends on the R^2 of the regression of the response variable Y on the regressor variable Xj.
d) A high leverage point is always highly influential.
e) Standardized residuals are always smaller than the ordinary residuals.
f) A residual plot of ei against u^ is more informative than that of ei against yi.
g) An outlier should always be rejected.
h) A Durbrin Watson statistic of zero indicates that all regressors are insignificant in predicting the response variable.
i) A Durbrin Watson statistic of 2 indicates the residuals are serially correlated.
j) A Durbrin Watson statistic meaures how influential an observation is in determining the regression line.
k) A Durbrin Watson statistic can be used to test the normaility of the residuals.
l) A Durbrin Watson statistic cannot be negative.