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CalcVerse

Standardabweichungsrechner

Calculate the standard deviation and variance of a data set, for a sample or a whole population, with a table of each value's deviation from the mean.

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So verwenden Sie diesen Rechner

  1. Enter your numbers separated by commas, spaces or line breaks.
  2. Choose sample (most common) or population.
  3. Review the deviation table to see how each value contributes.

Formel

Standard deviation measures how spread out values are around the mean. The sample formula divides by n − 1 (Bessel's correction) to give an unbiased estimate of the population variance.

Population: σ = √( Σ(x − μ)² / N )
Sample: s = √( Σ(x − x̄)² / (n − 1) )

Example

  1. Data: 2, 4, 4, 4, 5, 5, 7, 9; mean = 5.
  2. Squared deviations sum to 9 + 1 + 1 + 1 + 0 + 0 + 4 + 16 = 32.
  3. Population σ = √(32/8) = 2; sample s = √(32/7) ≈ 2.138.

Häufige Fragen

What does a large standard deviation mean?

Values are spread widely around the mean. A small standard deviation means values cluster closely around it.

What is the 68–95–99.7 rule?

For roughly normal data, about 68% of values fall within 1 standard deviation of the mean, 95% within 2 and 99.7% within 3.

Variance vs. standard deviation?

Variance is the average squared deviation; standard deviation is its square root, which has the same units as the data and is easier to interpret.