Struggling with part B to calculate the standard deviation. See the values I have tried (as a percentage) and have not worked. I tried entering both as a percentage and a decimal.

You are considering two stocks and have determined the following information: Stock A Return 29% 13 12 Probability of the Return 40% 55 5 Stock B Return 28 % 18 Probability of the Return 30% 60 7 10 a. Which of the two stocks has the higher expected return? Round your answers to two decimal places. The return on Stock A: 19.35 % The return on Stock B: 19.90 % Stock B has the higher expected return. b. Which stock is riskier? Do not round intermediate calculations. Round your answers to two decimal places. Standard deviation of Stock A: 5.22 Standard deviation of Stock B: 2.98 Stock A, is riskier. c. Given your answers to the two previous questions, what stock is preferred? is preferred. Stock B