Please ensure its ex post standard deviation fo returns, also explain how you got the result.

Calculate the ex post standard deviation of returns for the following: 60 percent, 40 percent, 30 percent, 45 percent, 65 percent. (Round intermediate calculations to 4 decimal places, e.g. 31.2125 and final answer to 2 decimal places, e.g. 15.25%.) Ex post standard deviation %