Suppose that the index model for stocks A and B is estimated from excess returns with the following results: RA = 2.0% + 0.4RM + eA RB = –1.8% + 0.9RM + eB σM = 15%; R-square A = 0.30; R-square B = 0.22 Break down the variance of each stock to the systematic and firm-specific components.