(Security market line) You are considering the construction of a portfolio comprised of equal investments in each of four different stocks. The betas for each stock are found below: (Click on the icon . in order to copy its contents into a spreadsheet.) a. What is the portfolio beta for your proposed investment portfolio? b. How would a 25 percent increase in the expected return on the market impact the expected return of your portfolio? c. How would a 25 percent decrease in the expected return on the market impact the expected return on each asset? d. If you are interested in decreasing the beta of your portfolio by changing your portfolio allocation in two stocks, which stock would you decrease and which would you increase? Why