Given the following frequency distribution, find the mean, variance, and standard deviation. Please show all of your work.

Class
Frequency

61-63
19

64-66
17

67-69
5

70-72
10

73-75
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.