The annual rate of return and related probabilities given below summarise your analysis for two securities.

Security A		Security B
Rate of Return	Probability	Rate of Return	Probability
10%	45%	5%	30%
14%	35%	15%	30%
18%	20%	25%	40%

Required:

a. Calculate the expected rate of return, E(R), for each security. b. Calculate the standard deviation, , for each security. c. Which security should you purchase? Explain why you make such choice.