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4. Suppose the expected return and standard deviation of the market portfolio are 11% and 20% respectively. The expected return of security A is 6%.The expected return of security B is 10% and its standard deviation is 18%. A portfolio that invests half of its value in security A and half in security B has a beta of 0.5. Use the CAPM to calculate the specific risk of security B. a 5. Summarize three ways to estimate investment risk and specify one way to include risk in investment evaluation