免费标准差计算器
计算数据集的标准差，衡量数据分布的离散程度。
标准差
8.164966
公式
## How to Calculate Standard Deviation ### Formula (Population) **σ = √[ Σ(xᵢ - μ)² / N ]** ### Steps 1. Find the mean (μ) of the data set 2. Subtract the mean from each value and square the result 3. Find the average of those squared differences 4. Take the square root For a **sample** standard deviation, divide by (N-1) instead of N.
计算示例
Find the standard deviation of 10, 20, and 30.
- 01Mean = (10 + 20 + 30) / 3 = 20
- 02Squared differences: (10-20)² = 100, (20-20)² = 0, (30-20)² = 100
- 03Variance (population) = (100 + 0 + 100) / 3 = 66.6667
- 04Standard Deviation = √66.6667 ≈ 8.1650
常见问题
What is standard deviation?
Standard deviation measures the amount of variation or dispersion in a data set. A low standard deviation means values are close to the mean; a high standard deviation means they are spread out.
What is the difference between population and sample standard deviation?
Population standard deviation divides by N (total count). Sample standard deviation divides by N-1 to correct for bias when estimating from a sample. Use sample when your data is a subset of a larger population.
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