You wish to calculate the risk level of your portfolio based on its beta.The five stocks in the portfolio with their respective weights and betas are shown in the accompanying table. Calculate the beta of your portfolio. stock: alpha, centauri, Zen Wren, Yukos: Portfolio weighs 20%, 10%, 15%, 20%, 35%; Beta: 1.15, 0.85, 1.60, 1.35, 1.85