Over the Past Four Years, the Common Stock of JL

Over the past four years, the common stock of JL Steel Co. produced annual returns of 7.2, 4.8, 10.2, and 12.6 percent, respectively. 3.2, 3.4, 4.2, and 4.5 percent, respectively. What is the standard deviation of the risk premium on JL Steel Co. stock for this time period?

A) 2.23 percent
B) 2.86 percent
C) 3.29 percent
D) 4.46 percent
E) 4.61 percent