Warunek normalności dla proporcji z próby

According to the admissions director of a certain college, approximately $11\mathrm{\%}$‍ of the $250$‍ freshmen admitted had applied using the early decision option. Suppose that we took random samples of $20$‍ freshmen from this population and computed the proportion $\hat{p}$‍ of freshmen in each sample who had applied using the early decision option. We can assume the admissions director's claim is true.