4. Assume that today's price of AAA stock is $23, and the next period price could be $28 or $21 with equal probabilities. Answer the following questions: a. What is the expected rate of return on AAA stock? b. What is the risk of AAA stock? c. Assume that you want to allocate your initial wealth of $1,000 on a portfolio that consists of one until of Telus stock and one unit of Shaw stock. If BBB stock is currently traded at $24, has an expected rate of return of 4 percent, variance of 900 and covariance between the two stocks is 25 . Find the expected rate of return on this portfolio and its risk