What is the expected standard deviation of stock A's returns based on the information presented in the table?

Outcome	Probability of outcome	Stock A return in outcome
Good	27%	57.00%
Medium	45%	19.00%
Bad	"?"	-49.00%

38.52% (plus or minus 0.02 percentage points)
		29.41% (plus or minus 0.02 percentage points)
		40.09% (plus or minus 0.02 percentage points)
		31.21% (plus or minus 0.02 percentage points)
		The expected standard deviation can not be estimated because the probability of the bad outcome is not given or the standard deviation can be computed from the given information, but none of the above is within 0.10 percentage points of the correct answer