4) An investment manager manages a risky portfolio. The expected rate of return on the risky portfolio is 20% and its standard deviation is 30%. The Treasury bill rate is 7%. A client wishes to invest 80% of a portfolio in the above fund and 20% in a T bill money market fund. The risky portfolio has investments in the following stocks with given proportion Stock A 28 % Stock B 34 % Stock C 38% a) Estimate the investment proportions of the client's overall portfolio including the (5 Marks) investment proportion in the Treasury bills?