免费方差计算器
计算数据集的方差，衡量数据偏离均值的程度。
Variance Pop
2.666667
Variance Sample4.000000
标准差1.632993
均值6.0000
公式
## How to Calculate Variance ### Formula (Population Variance) **σ² = Σ(xᵢ - μ)² / N** ### Steps 1. Find the mean (μ) 2. Subtract the mean from each value 3. Square each difference 4. Find the average of the squared differences Variance is the square of the standard deviation.
计算示例
Find the variance of 4, 8, and 6.
- 01Mean = (4 + 8 + 6) / 3 = 6
- 02Squared differences: (4-6)² = 4, (8-6)² = 4, (6-6)² = 0
- 03Variance (population) = (4 + 4 + 0) / 3 = 2.6667
- 04Variance (sample) = (4 + 4 + 0) / 2 = 4
常见问题
What is variance?
Variance measures how far a set of numbers is spread out from their average value. It is the average of the squared differences from the mean.
Why do we square the differences?
Squaring removes negative signs (so deviations above and below the mean don't cancel out) and gives more weight to larger deviations.
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