7. A research team collected data (yi, xi, x2i), i = 1,...,n, for n participants. Here y; was a sample of size 1 from Y, which was normally distributed with E(Y;) = Bxi + B2x2i and variance o. Then Y observations are independent. They seek to fit the model E(Y) = 1x1i + B2x2i, using Ordinary Least Squares by minimizing the function SS(b1, b2)==1(Yi - bx1i 1(yi bxi - b2x2i). a. Find a . a [SS(b1, b2)]. This part is worth 10 points. b. Find [SS(b1, b2)]. This part is worth 10 points. ab c. Specify the normal equations whose solution is . Do not solve for the OLS estimates. This part is worth 20 points. d. How many degrees of freedom will the sum of squared errors have? This part is worth 10 points. Save All Answers Save and Submit