Log-in | Contact Jeff | Email Updates
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: 9, 10, 12, 15, 17, 20, 21     Load another set of data

1Add up all the values.
Sum
104
2Square this sum
Sum Squared
10816
3Count the total number of values.
n
7
4Divide Sum Squared by the the total number of values
Avg. Sum Squared
1545.14
5Square each individual value. 
692 81
7102 100
8122 144
9152 225
10172 289
11202 400
12212 441
13Add up all these squared values.
Sum of Squares
1680
14Subtract Sum of Squares - Avg. Sum Squared 134.86
15Divide this by the total number of values minus 1.
sample variance
22.48
16Take the square root of the variance.
sample standard deviation
4.74

Check Answers

How well did you understand this lesson?

Avg. Rating 7.34 (73)

Not at all    Neutral    Extremely
012345678910

What didn't make sense?