3. There are two equally-probable states of the world; call them "good" and "bad". There are two securities: A and B. State of the world Good Bad Return to A 6 4 Return to B 4 8 Calculate the expected returns and standard deviations of three portfolios: one consisting of security A, one consisting of security B, and one consisting of y security A plus y security B. Compare the desirability of the portfolios. Calculate the covariance and correlation coefficient between A and B