Suppose the that stochastic discount factor is linear in the market return, Tm, as follows m = 0.8-1.74rm. 2 The historical market return is E (rm) 12%, and its standard deviation is 20%. What is the beta of a security that has and expected return of 15%? Plot the security market line. Suppose the that stochastic discount factor is linear in the market return, Tm, as follows m = 0.8-1.74rm. 2 The historical market return is E (rm) 12%, and its standard deviation is 20%. What is the beta of a security that has and expected return of 15%? Plot the security market line