The data below describe a three stock financial market that satisfies the single index model.

Stock

Capitalization

Beta

Mean Excess Return

Standard Deviation

A

$3,000

1.0

10%

40%

B

$1,940

0.2

2

30

C

$1,360

1.7

17

50

The single factor in this economy is perfectly correlated with the value weighted index of the stock market. The standard deviation of the market index portfolio is 25%.

a. What is the mean excess return of the index portfolio?

b. What is the covariance between stock B and the index?

c. Break down the variance of stock B into its systematic and firm specific components.