A particular cookie company has a double-feature box of cookies. These boxes come with two types of cookies; oatmeal raisin and chocolate chip. However, the proportion of cookies of each type varies. A data analyst working for the company wonders if there is a tendency for the boxes to have more of one type of cookie than the other. In order to investigate, he selects 54 boxes of the double-feature oatmeal raisin/choc -chip cookies and counts the number of each type of cookie. He finds out that, in his sample of 54 boxes, the proportion of chocolate chip cookies is 0.40. What is the standard deviation of the sampling proportion for the proportion of chocolate chip cookies ? Round your final answer to three decimal places and enter your final answer with three decimal places