Consider a portfolio consisting of equal holdings of two securities, S, and Sy. You have the following information about the securities: the return on S, is equally likely to be 5% or 10% pa the return on Sy is equally likely to be 10% or 20% pa. (a) Calculate the means and variances of returns on each individual security. (b) Calculate the mean and variance of the return on the portfolio as a whole, given that the correlation coefficient of the two securities is 0.7.