The following are estimates for two stocks.

stock	expected return	Beta	Firm-Specific standard deviation
A	14%	0.8	20%
B	19%	1.3	25%

The market index has a standard deviation of 23% and expected return of 7%. Risk free rate is 2%.

a. What are standard deviations of stock A and B.

b. What is the correlation coefficient between stock A and B.

c. Suppose we construct a portfolio with the 30% A and 40% B and 30% risk free rate. Compute the expected return, standard deviation, and beta for the portfolio.

Please explain a in detail.