Given the returns and probabilities for the three possible states listed here, calculate the covariance between the returns of Stock A and Stock B. For convenience, assume that the expected returns of Stock A and Stock B are 0.10 and 0.19, respectively.
Probability Return (A) Return (B)
Good 0.35 0.30 0.50
OK 0.50 0.10 0.10
Poor 0.15 - .025 - 0.30