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: 5, 7, 8, 11, 18, 19, 20     Load another set of data

1Add up all the values.
Sum
88
2Square this sum
Sum Squared
7744
3Count the total number of values.
n
7
4Divide Sum Squared by the the total number of values
Avg. Sum Squared
1106.29
5Square each individual value. 
652 25
772 49
882 64
9112 121
10182 324
11192 361
12202 400
13Add up all these squared values.
Sum of Squares
1344
14Subtract Sum of Squares - Avg. Sum Squared 237.71
15Divide this by the total number of values minus 1.
sample variance
39.62
16Take the square root of the variance.
sample standard deviation
6.29

Check Answers

How well did you understand this lesson?

Avg. Rating 7.63 (147)

Not at all    Neutral    Extremely
012345678910

What didn't make sense?