calculate the mean and standard deviation of the portfolio. The proportions invested in each stock are shown. a. United Health (UNH): 25%, United Technologies (UTX): 25%, Verizon (VZ): 25%, Walmart (WMT): 25% b. UNH: 10%, UTX: 20%, VZ: 30%, WMT: 40% c. UNH: 40%, UTX: 30%, VZ: 20%, WMT: 10% d. Which portfolio would a gambler choose? Explain. e. Which portfolio would a risk-averse investor choose? Explain.