) Consider the simple linear regression model given by = + for = 1 2 , where is an unknown constant and N 0 2 for all . Notice that there is no term in this regression equation. (a) What are () and ()? Based on your answer, obtain () and (), where = (1) P =1 . (b) By solving out the following minimization problem min X =1 ( ) 2 , obtain the least squares estimator of .