In: Finance
| 
 Economy Status  | 
 Probability  | 
 Stock A RETURN RA  | 
 Stock B RETURN RB  | 
| 
 BOOM  | 
 0.3  | 
  | 
 6%  | 
| 
 NORMAL  | 
 0.4  | 
 13%  | 
 7%  | 
| 
 BUST  | 
 0.3  | 
 33%  | 
 11%  | 
a: Expected returns
Stock A = 21.1%
Stock B= 7.90%
Standard deviations
Stock A= 8.31%
Stock B= 2.07%
b: Stock A is riskier since it has higher standard deviation
Workings
| State | Probability | Stock A | X^2*P | B | X^2*P | 
| Boom | 0.30 | 20% | 0.012 | 6% | 0.00108 | 
| Normal | 0.4 | 13% | 0.00676 | 7% | 0.00196 | 
| Bust | 0.3 | 33% | 0.03267 | 11% | 0.00363 | 
| Expected return | 21.10% | 7.90% | |||
| Sum | 0.05143 | 0.00667 | |||
| Variance | 0.006909 | 0.000429 | |||
| SD | 8.31% | 2.07% | |||
