Question 20 0 / 1 pts Consider the following returns and states of the economy for TZ.Com.: Economy Probability Return Weak 15% -1% 3% Normal 50% Strong 35% 6% What is the standard deviation of TZ's returns? SET YOUR CALCULATOR TO FOUR DECIMAL PLACES AND ROUND TO 2 DECIMAL PLACES AT THE END. DO NOT ENTER THE %. FOR EXAMPLE, IF YOUR ANSWER IS 7.70% ENTER IT AS 7.70. 2.5 2.31 margin of error +/- 0.01