Please answer the following questions completely and correctly.This is 4 subpart questions about portfolio choices. Thanks

2. This question is about portfolio choices. a) 15 marks] Consider two stocks with expected returns Er] 10% and EIrel 12%, standard deviations o 1 10% and az 15% and correlation 0.5. The risk-free rate is 5%. An investor with initial wealth 1000 additionally borrows 500 and invests equal amounts of available money in stocks 1 and 2. What are the expected return and standard deviation of the investor's portfolio? b) [6 marks] Consider portfolios A, B and C with the following expected returns EUrl and standard deviations o: Erl I 10.7% 11.3% 10.2% a 10.2% 12% 9.8% The portfolios are constructed by investing in stock 1 and stock 2 from part a) and a risk-free asset with return 5%. It is known that one of these portfolios is a tangency portfolio. Identify the tangency portfolio and its portfolio weights. c) 17 marksl Consider four portfolios A, B, c, and D with the following expected returns Erl and standard deviations A B C D Erl 10% 20% 10% 15% a 10% 30% 12% 30% It is known that two of the portfolios lie on the efficient frontier, and risk-free lending and borrowing are allowed. Identify the efficient portfolios, their Sharpe ratios, and the risk-free rate. d) [7 marks] Explain what is an efficient frontier. Suppose you are given an efficient frontier for portfolios of risky stocks. How would you construct the efficient frontier for portfolios of the same risky stocks and a risk-free asset with return rF