The following set of numbers respresents the average weekly scores of 9 preschoolers on a verbal aggression scale.
19.1, 18.9, 33.5, 18.7, 28.1, 31.5, 20.3, 30.1, 17.9
Consider this to be the entire population of scores. What is the standard deviation?
I already have the mean but I don't know how to figure out the rest.
Subtract each of the scores from the mean and square each difference. Find the sum of these squares. Divide that by the number of scores to get variance.
Standard deviation = square root of variance
I'll let you do the calculations.