$4-$ You manage a risky portfolio with an expected rate of return of $18\%$ and a standard deviation of $28\%.$ The T$-$bill rate is $8\%.(6$ Points$)$

a$.$ Your client chooses to invest $70\%$ of a portfolio in your fund and $30\%$ in an essentially risk$-$free money market fund. What are the expected value and standard deviation of the rate of return on his portfolio?

Suppose that your risky portfolio includes the following investments in the given proportions:

$\backslash$table$[[$Stock A$,25\%$