The CFO of Brady Boots has estimated the returns to Bradys stock, depending on the state of the economy. He has also compiled analysts expectations for the economy.

economy	probability	return
recession	0.1	-23%
below average	0.1	-8%
average	0.4	6%
above average	0.2	14%
boom	0.2	X

If the expected rate of return is 7.5%, then what is X? Also, compute the risk, measured as standard deviation of expected return, using the above probability distribution.