Question

What is the standard deviation of the following test scores? Round your answer to the nearest hundredth. 82, 76, 93, 82, 73, 80

Answer 1

First we find the mean (or the average)...
average : (82 + 76 + 93 + 82 + 73 + 80 / 6) = 486/6 = 81

now we subtract the average from every data point.....then square the result
82 - 81 = 1.......1^2 = 1
76 - 81 = -5....-5^2 = 25
93 - 81 = 12....12^2 = 144
82 - 81 = 1.......1^2 = 1
73 - 81 = -8.....-8^2 = 64
80 - 81 = -1.....-1^2 = 1

now we find the mean (or average) of those numbers
(1 + 25 + 144 + 1 + 64 + 1) / 6 = 236/6 = 39.33

that is ur variance....to find the standard deviation, take the square root of ur variance.....

square root 39.33 = 6.27 <==