A stock has had returns of 14%, 27%, 18%, and 5% for the past four years. Calculate the standard deviation of the returns.

Sure, here are the steps to calculate the standard deviation of the returns:

1. First, calculate the mean (average) of the returns. Add up all the returns and divide by the number of returns. In this case, (14% + 27% + 18% + 5%) / 4 = 16%.

2. Next, subtract the mean from each return to find the deviation of each return. This gives us -2%, 11%, 2%, and -11%.

3. Square each deviation to get the squared deviations. This gives us 0.04%, 1.21%, 0.04%, and 1.21%.

4. Find the mean of these squared deviations. This is called the variance. So, (0.04% + 1.21% + 0.04% + 1.21%) / 4 = 0.625%.

5. Finally, take the square root of the variance to get the standard deviation. The square root of 0.625% is approximately 7.91%.

So, the standard deviation of the returns is approximately 7.91%.