The past five monthly returns for Kohl's are 3.80 percent, 4.27 percent, 1.94 percent, 9.38 percent, and 2.82 percent.

How do i compute the standard deviation of Kohls' monthly returns?

I keep getting 10.02 or 10.01 and it is not correct.

(3.80+4.27+-1.94+9.38+.2.82)/5 = 12.69/5= 2.538

(3.80-2.538)^2+( 4.27-2.538)^2+ (-1.94-2.538)^2+ (9.38-2.358)^2+(-2.82-2.358)^2)^.5= 100.16608^.5 = 10.008

which would be rounded to 10.01