4. Consider a CAPM economy. The risk free rate (rf) is 3% and the expected market return (rM) is 11%. Compute the expected return of the following stocks or portfolios. Total: 20 marks. (a) Stock 1: =0.80. (5 marks) (b) Stock 2:=1.20. (5 marks) (c) Portfolio 1: The proportions invested in stock 1, stock 2, and risk free asset are 40%,40%, and 20%, respectively. (5 marks) (d) Portfolio 2: The proportions invested in stock 1, stock 2, and risk free asset are 60%,70%, and 30%, respectively. ( 5 marks)