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The Standard Deviation :: Standard Deviation Calculation
Calculate the Standard Deviation for the following data using the calculator to the right (round to 1 decimal points). Click on the Check Answer button to see how you did.

Data: 2, 6, 12, 13, 18, 19, 21     Load another set of data

1Add up all the values.
Sum
91
2Count the total number of values.
n
7
3Divide the Sum by the the total number of values.
Mean
13
4Subtract the mean from each value. Then Square that result.

ValueValue-Mean(Value-Mean)2
2 -11 121
6 -7 49
12 -1 1
13 0 0
18 5 25
19 6 36
21 8 64
5Add up all the squared deviations.
Sum of Squared Deviations
296
6Divide the Sum of Squared Deviations by n-1.
Sample Variance
49.3
7Take the square root of the variance.
sample standard deviation
7

Check Answers

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