Suppose that you are considering investing in three mutual funds. The first is a stock fund, the second is a long-term government and corporate bond fund, and the third is a T-bill money market fund that yields a risk-free rate of 2%. You can also borrow at the risk-free 2% rate. The expected returns and standard deviations of the risky funds are:

	Expected Return	Standard Deviation
Stock fund (S)	10%	15%
Bond fund (B)	4%	8%

The correlation coefficient between the returns of stock fund and bond fund, is 0.2

You can invest only in the stock fund and the bond fund . You want an expected return of 8%. What is the standard deviation of your portfolio?