13. Suppose the same client in the previous problem decides to invest in your risky portfolio a proportion (y) 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? \begin{tabular}{ll} \hline Stock A & 27% \\ Stock B & 33% \\ Stock C & 40% \\ \hline \end{tabular}