4. You are contemplating investments in IBM, Apple, and General Motors. The S&P 500 is used as a broad measure of overall market performance. You gather the following data. Required Return Standard Deviation IBM Apple General Motors S&P 500 14.5 16.0 15.0 11.3 17.0 20.5 21.0. 13.5 a. You first consider a portfolio consisting of IBM and Apple. If the correlation coefficient between IBM and Apple is .87, what is the standard deviation of a portfolio with 45% of value in IBM and 55% in Apple?. b. If you instead formed a portfolio with 45% of value in IBM and 55% in General Motors. Oould you expect the standard deviation of this portfolio to be higher, lower, or the same (as the standard deviation of the portfolio that you calculated in the above part a). Briefly explain why. No additional calculations are necessary