Consider a portfolio made up of two stocks, S, an S2. The variance of the 1-year returns on the two stocks are denoted 02 and 02?. [a] Assume we construct a portfolio consisting of long positions in the two stocks. Explain why the variance of the 1-year return on the portfolio can't exceed the larger of 012 and 02?! Suppose we invest $150 in a stock Si: $100 of our own capital $50 of borrowed 1-year money (at an interest rate of 3%) Let Ri denote the 1-year return on St. Let E[R1] = u. [b] In terms of o2 what's the expected value and variance of the 1-year return on our $100 investment