Please show all work. Thank you!

13. Suppose the same client in the previous problem decides to invest in your risky portfolio a proportion () of his total investment budget so that his overall portfolio will have an expected rate of return of 15%. (LO 5-3) 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