Returns for the Dayton Company over the last 3 years are shown below. What's the standard deviation of the firm's returns? (Hint: This is a sample, not a complete population, so the sample standard deviation formula should be used.) Do not round your intermediate calculations.

Year		Return
2013		21.00%
2012		-12.50%
2011		35.00%

a. 18.79%

b. 30.02%

c. 23.43%

d. 27.09%

e. 24.41%