Definition & Details
The **median** is a measure of central tendency, which means it helps describe the "center" of a set of data. To find the median, you must first arrange all the numbers in your list from the smallest to the largest (or largest to smallest).
- If there's an odd number of values: The median is the single number exactly in the middle.
- If there's an even number of values: The median is the average (mean) of the two middle numbers.
The median is useful because it's not affected by extremely high or low values (outliers) as much as the mean can be.
Examples
- Odd Number of Values: Find the median of 5, 2, 9, 1, 7.
1. Order the numbers: 1, 2, 5, 7, 9
2. The middle number is 5. So, the median is 5. - Even Number of Values: Find the median of 10, 4, 8, 2.
1. Order the numbers: 2, 4, 8, 10
2. The two middle numbers are 4 and 8.
3. Calculate their average: (4 + 8) / 2 = 12 / 2 = 6. So, the median is 6. - Student Test Scores: Scores are 75, 80, 90, 85, 95.
Ordered: 75, 80, 85, 90, 95. Median = 85.
Synonyms
Middle value, central value, midpoint (in an ordered set).
Fun Fact!
When you hear about "median income" or "median house price," it's often used instead of the average (mean) because it gives a more typical picture. If a few very rich people or very expensive houses were included, the mean could be much higher than what most people experience, but the median would still represent the true middle.