Given the following SAS code and ouput: proc reg data=final; model y=x1-x4 / vif spec; Source DF Mean Square F Value Pr > F Sum of Squares 182324999 2683827 185008826 186.82 Model Error Corrected Total <.0001 root mse dependent mean coeff var r-square adj r-sa parameter estimates variable estimate df standard error t value pr> lt Variance Inflation Intercept x1 x2 x3 x4 1 1 1 1 1 50084 56.26268 0.03526 -0.85380 -0.54954 5942.71943 102.93970 0.01036 0.24339 0.28995 8.43 0.55 3.40 -3.51 -1.90 <.0001 test of first and second moment specification df chi-square pr> Chisa 14 13.36 0.4982 %, in the population is % The proportion of variation in Y that is predictable from the X's in the sample is and the expected value of Y when all the X's are set at O is