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1. Suppose that you have the opportunity to buy stock in AT&T and Microsoft. AT&T Microsoft Mean 0.10 Standard Deviation O. 15 0.21 0.25 (a) What is the expected return of a portfolio made up of half AT&T and half Microsoft? (b) Assume the correlation between the two stocks is 0.5. What is the variance of a portfolio made up of half AT&T and half Microsoft? (c) Now assume that the correlation between AT&T and Microsoft is 1. Find the weights of the two stocks that produce a minimum risk portfolio. What is the variance of this portfolio?