10. What is the expected standard deviation of stock As returns based on the information presented in the table?

Outcome	Probability of outcome	Stock A return in outcome
Good	20.0%	75.0%
Medium	50.0%	14.0%
Bad	30.0%	-40.0%

A. 40.04% (plus or minus 0.10 percentage points) (RIGHT ANSWER IS A)

B. 43.86% (plus or minus 0.10 percentage points)

C. 57.54% (plus or minus 0.10 percentage points)

D. 46.98% (plus or minus 0.10 percentage points)

E. The expected standard deviation can not be estimated because the probability of the bad outcome is not given or the standard deviation can be computed from the given information, but none of the above is within 0.10 percentage points of the correct answer

PLEASE SHOW WORK AND EXPLAIN. I USED THESE FORMULAS AND I GOT THE WRONG ANSWER:

Variance of returns based on future outcomes = {p(1) [R(1) E(R)]2} + {p(2) [R(2) E(R)]2} =

Standard deviation of returns based on future outcomes = variance of returns based on future outcomes

Thank you!