The probability of the economy booming is 8 percent, while it is 70 percent for being normal, and 22 percent for being recessionary. A stock is expected to return 18.3 percent in a boom, 7.4 percent in a normal economy, and lose 6.4 percent in a recession. What is the standard deviation of the returns?

Multiple Choice

a. 7.32%

b.6.72%

c.6.94%

d.6.84%

e.8.61%