Statistiques et probabilités
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Chebyshev's Theorem Calculator.
Find the minimum proportion within k standard deviations.
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Les résultats se mettent à jour pendant la saisie.
Results update automatically as you type.
Use Cases
Quality Control
Determine the minimum percentage of products within a specified number of standard deviations from the mean, without assuming a normal distribution.
Example: If k=3, at least 88.89% of items are within 3 standard deviations.
Data Analysis
Quickly assess the spread of data in any dataset, especially when the distribution is unknown or skewed.
Example: For k=2, you know at least 75% of data lies within 2 standard deviations.
Frequently Asked Questions
- What does Chebyshev's Theorem calculate?
- It calculates the minimum proportion of data that must lie within k standard deviations from the mean, for any distribution. The formula is 1 - 1/k², expressed as a percentage.
- Can I use this calculator for any data set?
- Yes, Chebyshev's Theorem applies to any distribution, regardless of shape. It provides a conservative lower bound, so the actual proportion within k standard deviations is at least the calculated value.
- What is the minimum value for k?
- k must be greater than 1. For k=1, the theorem gives 0%, which is trivial. For k=2, it guarantees at least 75% of data within 2 standard deviations.
Tips & Common Mistakes
Tips
- Enter a value greater than 1 for k. The larger the k, the higher the minimum proportion.
- Use this calculator as a quick reference for statistical analysis or to check if your data meets certain spread criteria.
- Remember that Chebyshev's Theorem gives a lower bound; the actual proportion may be higher, especially for bell-shaped distributions.
Common Mistakes to Avoid
- Entering k=1 or less, which yields a meaningless result (0% or negative).
- Assuming the result is the exact proportion; it is only a minimum guarantee.
- Using this theorem for small samples without considering sample size limitations.
Last updated: August 13, 2026