Statics
posted by kesha .
Given the following frequency distribution, find the mean, variance, and standard deviation. Please show all of your work.
Class
Frequency
6163
19
6466
17
6769
5
7072
10
7375
12

Use the midpoint of the intervals to determine values.
Find the mean first = sum of scores/number of scores
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.