You have the following stocks over the past 5 years. The holding period returns are given. What is the standard deviation of a portfolio's return in which 80% of your portfolio is invested in UBX and 20% is invested in Red Creek? I want you to calculate this two ways: You should get the same answer. Using the formula: Estimated Standard deviation = Squareroot (sigma^n_t = 1 (r_t - r_avg)^2)/(n - 1) Using the formula: Standard deviation of a 2 asset portfolio: sigma_2 = Squareroot W^2_a sigma^2_a + w^2_b sigma^2_b + 2w_a w_b rho_ab sigma_a sigma_b