Consider the model y-80 + β1x1 + β2x2 + β3x3 +e, where x1 is a quantitative variable and x2 and x3 are dummy variables describing a qualitative variable at three levels using the coding schemex2 - y 45.5+ 1.7x1 + 11.5x2 + 16.7x3. Complete parts a and b a. What is the response line (equation) for E(y) when x2 x3 0? When x2 1 and x3 0? When x2 0 and x3-1? Choose the correct equation for x2 x3 0 1 if level2 1 if level3 and x3- . The resulting least squares prediction equation is 0 otherwise 0 otherwise Choose the correct equation for x2 1 andx3-0 Choose the correct equation for x2 0 andx3-1 b. What are the least squares prediction equations associated with level 1, level 2, and level 3? The equation for level 1 is Ey)x The equation for level 2 is E(y) = The equation for level 3 is E(y)-D+D-1 Choose the correct graph of these three lines below. OA Ов. O C. Y L2 L3 し2 L1 L1 5 L3 5 L3 -5