Comprehensive Calculator Guide
This calculator measures how lopsided your data are: a tail toward large values (positive skew) or small ones (negative skew), using the sample skewness as in Excel. Salaries with one high pay skew 2.57, strongly right, so the mean of 10,143 is well above the median of 7,800.
Skewness
Positive skew: long right tail, mean above median; negative: long left tail. Rule of thumb: |skew| < 0.5 roughly symmetric, 0.5–1 moderate, > 1 strong. Skewed data favour the median and may break normal-based tests.
How to Use
- Enter at least three values.
- No need to sort.
- Press “Calculate” to see the skewness and direction.
Formula Used
g = n ÷ ((n − 1)(n − 2)) × Σ((x − x̄) ÷ s)³
Practical Examples
- Example 1
- Salaries: 2.57.
- Example 2
- Easy test: −2.42.
Important Tips
- Compare mean and median.
- Plot first.
- Use 30+ values.
Common Mistakes to Avoid
- Mixing up the direction.
- Tiny samples.
- Using only the mean.
Frequently Asked Questions
- Positive skew?
- A long right tail.
- Symmetric?
- Near zero.
- Why do programs differ?
- Sample vs population formulas.