Calculate Variance
Understanding Variance
Variance is a statistical measurement of the spread between numbers in a data set. More specific, variance measures how far each number in the set is from the mean and thus from every other number in the set.
Example Calculation
For a sample data set {3, 7, 8}, the steps to calculate variance are:
- Calculate the mean (average): (3 + 7 + 8) / 3 = 6
- Subtract the mean and square the result for each number:
- (3 - 6)² = 9
- (7 - 6)² = 1
- (8 - 6)² = 4
- Average those squared results: (9 + 1 + 4) / 3 = 4.67