Calculate the standard deviation of return for each individual investment.

Shown below are two investment options. Each will generate return within one year with different sets of probabilities. The one-year period holding returns with corresponding probabilities for each investment option, A and B are as follows: Possible rate of return -0.01 0.02 0.07 0.1 0.15 0.2 B Possible rate of return Probability Probability 0.05 0.05 0.1 0.25 0.25 0.3 -0.04 0.05 0.1 0.25 0.3