Problem 6.1. The probability distribution of returns on stocks X and Y follows. Probabilit 0.2 0.3 0.3 0.2 y Rx -20 0% 20 40 % % % Ry 1% 3% 5% 7% Calculate the expected return and the standard deviation of return of a portfolio that invests $6000 in X and $4000 in Y.