4. You manage a risky portfolio with an expected return of 17% and a standard deviation of 27%. The T-bill rate is 5%. (a) Your client chooses to invest 70% of a portfolio in your fund and 30% in a T-bill money market fund. What is the expected value and standard deviation of the rate of return on your client's portfolio? (b) Suppose that your risky portfolio includes the following investments in given proportions: Stock A: 27% Stock B: 33% Stock C: 40% What are the investment proportions in your client's overall portfolio including the position in T-bills? (c) What is the Sharpe (reward-to-volatility) ratio of your risky portfolio? Your client's? (d) Suppose your client decides to invest in your portfolio a proportion y of the total investment budget so that the overall portfolio will have an expected rate of return of 15%. What is the proportion y ? What is the standard deviation of the rate of return on your client's portfolio