3.An investor invests 60% of his wealth in a risky asset with an expected rate of return of 12% and a variance of 4%, and 40% in a treasury bill (risk-free asset) that pays a rate of 3%. Calculate the expected return and standard deviation of his portfolio.??

4.You have $2000 available to invest. The risk-free rate is 3%. The return and standard deviation on the risky portfolio is 8% and 12%. You wish to construct a portfolio with 10% standard deviation. How much ($ amount) should you invest in the risky portfolio?