Calculate the mean, variance and standard deviation of the distribution of scores listed in number 4 above. Show your work so your instructor can provide feedback. (4 points)

the numbers are as follows. 1,8,9,22,45,57,63,73,76,79,81,83,89,92,99 when i calculate the variance, i keep getting a neg number. I've tried it too different ways. Hence, i cannot get a SD. please help. I've been using this formula s2=EX2-(Ex)^2/n n-1

--Answer below:

Calculate the mean: 1+8+9+22+45+57+63+73+76+79+81+83+89+92+99=877 877/15=58.5