These are the three most common ways to find the "center" of a data set:
- Mean: The arithmetic average. Sum all values and divide by count.
- Median: The middle value when data is sorted. Less affected by outliers.
- Mode: The most frequently occurring value. A set can have no mode, one mode, or multiple modes.
Example
Data: 3, 7, 7, 2, 9
- Mean: (3+7+7+2+9) ÷ 5 = 5.6
- Median: Sort → 2, 3, 7, 7, 9 → middle value = 7
- Mode: 7 appears most often = 7
When to Use Each
Use mean for symmetric data. Use median when there are outliers (e.g., income data). Use mode for categorical data (e.g., most popular color).