Skewness Calculator
Estimate the skewness of a distribution using Pearson's approximation based on the mean, median, and standard deviation.
Pearson Skewness Coefficient
1.5000
Pearson Skewness Coefficient vs Mean
Formule
## How to Estimate Skewness ### Pearson's Second Coefficient of Skewness **Skewness = 3 * (Mean - Median) / Standard Deviation** - Positive skewness: The right tail is longer; the mean exceeds the median. - Negative skewness: The left tail is longer; the mean is below the median. - Zero skewness: The distribution is symmetric. This is an approximation. The exact moment-based skewness requires raw data.
Exemple Résolu
A dataset has mean 55, median 50, and SD 10. Estimate the skewness.
- 01Skewness = 3 * (55 - 50) / 10
- 02= 3 * 5 / 10
- 03= 15 / 10 = 1.5
- 04Positive value indicates right skew
Questions Fréquentes
What does positive skewness mean?
The distribution has a longer right tail. Most values cluster to the left, with some high outliers pulling the mean above the median. Income distributions are typically positively skewed.
What skewness value is considered significant?
A rough guideline: |skewness| < 0.5 is approximately symmetric, 0.5-1 is moderately skewed, and > 1 is highly skewed.
Why use Pearson's approximation?
It requires only three summary statistics (mean, median, SD) rather than the entire raw dataset. It works well for unimodal, moderately skewed distributions.
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