What would be the standard deviation

Barbara is considering investing in a stock and is aware that the return on that investment is particularly sensitive to how the economy is performing. Her analysis suggests that four states of the economy can affect the return on the investment. Using the table of returns and probabilities below, find

Probability

Return

Boom	0.4	25.00%
Good	0.1	15.00%
Level	0.4	10.00%
Slump	0.1	-5.00%

What is the standard deviation of the return on Barbara's investment?(Round intermediate calculations and answer to 5 decimal places, e.g. 0.07680.)

Standard deviation