You find a certain stock that had returns of 15.4 percent, –22.7 percent, 28.7 percent, and 19.7 percent for four of the last five years. Assume the average return of the stock over this period was 13.40 percent. Requirement 1: What was the stock’s return for the missing year? (Do not round intermediate calculations. Enter your answer as a percentage rounded to 2 decimal places (e.g., 32.16).) Stock's return % Requirement 2: What is the standard deviation of the stock’s returns?