Answer:
Step-by-step explanation:
a. Expected return:
This will be a weighted average of the returns in different states. 
= (25% * 15%) + (25% * -22%) + (50% * 7%)
= 1.75%
b. Standard deviation:
= √ Variance 
= √(25% * (15% - 1.75%)²) + (25% * (-22% - 1.75%)²) + (50% * (7% - 1.75%)²)
= √0.01986875
= 14.10%