Suppose that there are four risky securities S1, S2, S3, S4 and suppose that among all portfolios whose expected return is 5 the minimal risk has the portfolio with the weights (10%, 20%, 30%, 40%). Suppose that among all portfolios with expected return 10 the minimal risk has the portfolio with weights (15%, 25%, 35%, 25%). Among all portfolios with expected return 8, find the one with the minimal risk