MsGonzalez Has Recorded the Test Scores for Each of Her $\Sigma X^{2}$

Essay

Ms.Gonzalez has recorded the test scores for each of her 25 students.She has calculated $\Sigma X^{2}$ = 320 and $\left(\sum X\right)^{2}$ = 5,000.Calculate the estimated population standard deviation for her data.