Login

Contact Jeff

Email Updates
About
Stats Q&A
Calculators
Tutorials
Products
Home
View All Tutorials
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:
1, 10, 11, 13, 16, 20, 21
1
Add up all the values.
Sum
92
2
Count the total number of values.
n
7
3
Divide the Sum by the the total number of values.
Mean
13.1
4
Subtract the mean from each value. Then Square that result.
Value
ValueMean
(ValueMean)
^{2}
1
12.1
146.4
10
3.1
9.6
11
2.1
4.4
13
0.1
0
16
2.9
8.4
20
6.9
47.6
21
7.9
62.4
5
Add up all the squared deviations.
Sum of Squared Deviations
278.8
6
Divide the Sum of Squared Deviations by n1.
Sample Variance
46.5
7
Take the square root of the variance.
sample standard deviation
6.8
View All Tutorials
How well did you understand this lesson?
Avg. Rating 8.35 (162)
Not at all
Neutral
Extremely
0
1
2
3
4
5
6
7
8
9
10
What didn't make sense?
Name
Email
Not Published
Comment
To prevent comment spam, please answer the following question before submitting (tags not permitted) :
What is 2 + 4:
(enter the number)
September 9, 2013  Megan Garcia wrote:
why does the calculator say that 1212.9=0.9000000000000004 ?
February 2, 2013  Elsy wrote:
Great explanation, tools and visuals. Thank you.
June 12, 2012  Dennis wrote:
How do I divide in step 6
April 17, 2010  Marie wrote:
sample variance did not make sense. Divide the sum of squared deviations n1
September 21, 2009  anonomous wrote:
This was an excellent tutorial on stsndard deviation. Thank Y
September 15, 2009  Dave Mills wrote:
Excellent course! Thnak you!
March 18, 2009  Omar wrote:
Why do you divide the Sum of Squared Deviations by n1 to get the sample variance?