Lets assume the following about the possible yields on assets A and B:

Scenario	Probability of Scenario	Yield on asset A	Yield on asset B
I	10%	-10%	-20%
II	20%	16%	18%
III	40%	25%	25%
IV	30%	3%	29%

Please caclulate the standard deviation of the yields of assets A and B and present the standard deviation of the riskiest asset as an answer.