4. Suppose there are three uncorrelated assets. Each has a variance of 1.0 and expected rates of return are 1, 2, and 3, respectively. For this example, short sales are allowed. Do the following: a. Find the minimum variance portfolio for the following desired expected portfolio rates of return: 1.0, 1.5, 2.0, 2.5, and 3.0. b. Sketch these on the return versus risk plot (you will need to use the standard deviation of the portfolio, which clearly equals sqrt(w1^2+w2^2+w313), where wi are the weights). C. Suppose we have a risk-free asset with a return of 2%. Modify your plot for b