You have decided to invest in an equally weighted portfolio consisting of American Express, Proctor & Gamble, Home Depot, and E. I. du Pont and need to find the beta of your portfolio. Go to finance.yahoo.com, find the ticker symbol of each company and thereby find the beta of each company. Please illustrate how you calculate the beta of the entire portfolio. Without adding new assets, how would you adjust the portfolio to make it more aggressive? Less aggressive?