Variance
Definition of Variance
- Variance is a statistical measure that tells us how measured data vary from the average value of the set of data.
- In other words, variance is the mean of the squares of the deviations from the arithmetic mean of a data set.
More about Variance
- Variance is the square of the standard deviation.
- The formula for variance is
Solved Example on Variance
Find the variance of the data set {1, 2, 3, 4, 10}.
Choices:
A. 10
B. 9
C. 8
D. 7
Correct answer: A
Solution:
Step 1: The mean of the data set {1, 2, 3, 4, 10} is 
.
[Use the formula for mean.]
Step 2: The standard deviation of the data set is
[Use the formula for mean.]
Step 3: 
Step 4: The variance of the data set is 
. [Substitute 
.]
Related Terms for Variance
- Arithmetic Mean
- Standard Deviation
Additional Links for Variance
