Securities M and N are equally risky, but they have different expected returns: Calculate the portfolio variance if Cor_mn = +1.0, Cor_mn= -1.0, Cor_mn = +0.1 and Cor_mn= -0.1. An investor holds two securities X and Y in equal proportions with the following risk and return characteristics: The returns of these securities have a positive correlation of 0.6. Calculate the portfolio return and risk. Define risk. Giving examples, explain the two main types of risks