# Standard deviation

The common stock of US Air Inc. had annual returns of 15.6 %, 2.4 % , -11.8 % and 32.9% over the past 4 years respectively. What is the standard deviation of these returns.?

a. 13.29 percent

b. 14.14 percent

c. 16.50 percent

d. 17.78 percent

e. 19.05 percent

https://brainmass.com/business/finance/standard-deviation-common-stock-usa-air-inc-335972

#### Solution Preview

to calculate std. dev, we first need the mean (for simplicity, i will omit the % sign for now, so 15.6% is just 15.6, I will add it back later)

mean = ...

#### Solution Summary

The expert examines standard deviation for common stock of the United States Air Inc.

$2.19