3. (5+4=9 points ) In fitting a least squares line to n=18 data points, the following quantities were computed (note you do not need the actual observations): x=15.2,y=68.5,SSxx=71.82,SSyy=250.48,SSxy=110.62. a) Find the regression line relating y to x. Predict y when x=12. b) Compute SSE and MSE. What does the Square Root of MSE tell us