What is mean, median, and mode?
These are the three most common measures of central tendency—ways to describe a "typical" value in a list. The mean is the arithmetic average. The median is the middle after sorting (or the average of the two middle values). The mode is the value that appears most often.
Difference between mean vs median vs mode
The mean uses every number, so it is sensitive to very large or small outliers. The median only cares about order, so it is more robust for skewed data. The mode is about repetition—ideal for categorical-style numeric codes or finding the most common score, and there may be zero, one, or several modes.
When to use each?
- Mean: symmetric data, no extreme outliers, same units as your measurements.
- Median: incomes, house prices, reaction times—anything with occasional extremes.
- Mode: most common category or score; useful when you care about frequency, not averaging.
Examples
- Data 2, 3, 3, 4 → mean 3, median 3, mode 3.
- Data 1, 2, 99 → mean 34, median 2 (median resists the outlier).
- Data 1, 1, 2, 2 → two modes: 1 and 2 (bimodal).