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The Standard Deviation :: Standard Deviation Calculation Short-Cut Method
This method might be a bit faster to calculate. 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, 3, 4, 12, 15, 17, 20     Load another set of data

1Add up all the values.
Sum
73
2Square this sum
Sum Squared
5329
3Count the total number of values.
n
7
4Divide Sum Squared by the the total number of values
Avg. Sum Squared
761.29
5Square each individual value. 
622 4
732 9
842 16
9122 144
10152 225
11172 289
12202 400
13Add up all these squared values.
Sum of Squares
1087
14Subtract Sum of Squares - Avg. Sum Squared 325.71
15Divide this by the total number of values minus 1.
sample variance
54.29
16Take the square root of the variance.
sample standard deviation
7.37

Check Answers

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