You have a portfolio which is comprised of 45 percent of stock A and 55 percent of stock B. What is the portfolio standard deviation?

State of the Economy	Probability	E(R) A		E(R) B
		45%		55%
Boom	0.22	32.0		50.0
Normal	0.60	9.00		30.0
Recession	0.18	(30.0	)	(12.0	)

		18.06 percent
		17.89 percent
		19.77 percent
		20.00 percent
		17.56 percent