=8.8. Reconsider the portfolio selection example given in Section 8.2. A fourth stock (stock 4) now has been found that gives a good balance between expected return and risk. Using the same units as in Table 8.2, its expected return is 17% and its risk is 18%. Its joint risk per stock with stocks 1, 2, and 3 is 0.015, 0.025, and 0.003, respectively.