The Common Stock of Air Express Had Annual Returns of 11.7

Multiple Choice

The common stock of Air Express had annual returns of 11.7 percent, 8.8 percent, 16.7 percent, and −7.9 percent over the last four years, respectively. What is the standard deviation of these returns?

A) 8.29 percent
B) 9.14 percent
C) 11.54 percent
D) 7.78 percent
E) 10.66 percent