a) How is an efficient frontier constructed and how can it be used to determine the optimal portfolio for an investor? (20 marks) b) Stock X has a beta of 0.60 with the relevant market return. The market return is 16%, and the market variance is 12%. Stock X has an average annual return of 13% and its variance is 9%. Using the Single Index Model, calculate the alpha and unique risk for Stock X and comment on how these measures are used in portfolio construction. (15 marks)