Problem 7. (15 points) Suppose your investment portfolio consists of three assets: Apple stocks, Walmart stocls, and the risk-free T-bills. The following table lists how many units of each of the three assets you own, along with the price per unit of asset. Number of units owned Price per unit Expected return Asset Apple stocks Walmart stocks T-bills 200 200 12 $70 $1000 0 10-10% 004-4% (a) (5 points) What is the expected return of your investment portfolio? (b) (5 points) Suppose that the variance of each of the two stocks are 2ppe = 0.12 and 21 art-0.05, and the covarance between the two stocks is AppleWi ,--0.1. What is the vanance of your entire investment portfolio? (e) (5 points) What is the Sharpe ratio of your investment portfolio