Given the following information, what is the standard deviation of the returns of a portfolio that is invested 37 percent in Stock Q and 63 percent in Stock R?

state of economy	boom	normal
probability	65%	35%
stock Q Return	16%	9%
stock R Return	15%	13%

a. 1.92 percent

b. 2.20 percent

c. 0.93 percent

d. 1.84 percent

e. 1.51 percent