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Standard Deviation Calculator — Sample & Population Variance with Steps

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Calculated result

Sample SD 2.1381

Variance: 4.5714 · Mean: 5 · n: 8

Sum: 40 · Sum of squared deviations: 32

Population SD: 2 · Sample SD: 2.1381

Standard error: 0.7559

Coefficient of variation: 42.7618%

Tukey outliers: none

Deviation table

xx − mean(x − mean)²zFlag
2-39-1.4031
4-11-0.4677
4-11-0.4677
4-11-0.4677
5000
5000
7240.9354
94161.8708
Show the working
  1. 1. Mean = 40 ÷ 8 = 5.
  2. 2. For each value, calculate x − mean and square that deviation; Σ(x−mean)² = 32.
  3. 3. Sample variance = Σ(x−x̄)² ÷ (n−1) = 4.5714.
  4. 4. Standard deviation = √4.5714 = 2.1381.

Choose Sample when these observations are a subset used to estimate a larger population; choose Population when the dataset contains every observation in the population you mean to describe.

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