You manage a risky portfolio with an expected rate of return of 10% and a standard deviation of 37%. The T-bill rate is 4%. Suppose that 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 9%. Required: a. What is the proportion y ? b. What are your client's investment proportions in your three stocks and the T-bill fund? c. What is the standard deviation of the rate of return on your client's portfolio