What is the difference between mean, median, and mode?

The mean is the arithmetic average (sum divided by count). The median is the middle value when data is sorted. The mode is the most frequently occurring value. Mean is sensitive to outliers, while median is more resistant to extreme values.

When should I use standard deviation versus variance?

Standard deviation is the square root of variance and is in the same units as your original data, making it easier to interpret. Variance is useful for mathematical calculations and shows the spread of data squared. Use standard deviation for practical interpretation.

What does the interquartile range (IQR) tell me?

The IQR is the difference between the third quartile (Q3) and first quartile (Q1). It represents the middle 50% of your data and is used to identify outliers. Values below Q1 - 1.5×IQR or above Q3 + 1.5×IQR are typically considered outliers.

How do I interpret a histogram and box plot?

A histogram shows the frequency distribution of your data across different ranges (bins). It reveals patterns like skewness and modality. A box plot displays the five-number summary and makes it easy to identify outliers (shown as individual points beyond the whiskers).

Descriptive Statistics

Compute summary statistics, visualize distributions, check normality, and detect outliers.

📚 Learn How to Use This Calculator

New to statistics? Learn how to calculate and interpret descriptive statistics with our comprehensive guide.

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Notes & Assumptions

• Missing values excluded pairwise. • Normality tests require n ≤ 5000 (Shapiro). • Outliers flagged by method thresholds.
• For grouped data, stats computed per group; charts facet by group. • Decimal precision configurable.

Learn More

📘 Descriptive statistics guide · 📘 Normality tests explained · 📘 Outlier detection methods

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