Kurtosis Formula:
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Kurtosis is a statistical measure that describes the degree to which a probability distribution is tailed or peaked compared to the normal distribution. It measures the "tailedness" of the data distribution.
The calculator uses the kurtosis formula:
Where:
Explanation: Kurtosis measures the fourth standardized moment of a distribution. Higher kurtosis indicates more extreme outliers, while lower kurtosis indicates fewer outliers.
Details: Kurtosis is crucial for understanding the shape of data distributions, identifying outliers, assessing risk in financial data, and ensuring proper statistical modeling assumptions.
Tips: Enter numerical data points separated by commas. The calculator will compute the mean, standard deviation, and kurtosis of your dataset.
Q1: What do different kurtosis values mean?
A: Normal distribution has kurtosis ≈ 3. Values > 3 indicate heavy tails (leptokurtic), values < 3 indicate light tails (platykurtic).
Q2: What is excess kurtosis?
A: Excess kurtosis = kurtosis - 3. This centers the normal distribution at 0 for easier interpretation.
Q3: When is high kurtosis problematic?
A: High kurtosis indicates more outliers, which can violate normality assumptions in statistical tests and affect model performance.
Q4: How does kurtosis differ from skewness?
A: Skewness measures asymmetry, while kurtosis measures tail heaviness and peakness relative to normal distribution.
Q5: What are typical kurtosis ranges in real-world data?
A: Financial returns often show high kurtosis (>5), while manufactured processes typically have kurtosis near 3.