Median

Definition

The median is the middle value in a data set when the values are arranged in ascending or descending order. If the data set has an even number of observations, the median is the average of the two middle numbers.

5 Must Know Facts For Your Next Test

1. The median is a measure of central tendency that is not affected by extreme values (outliers).
2. To find the median, first arrange all data points in numerical order.
3. For an odd number of observations, the median is the middle value.
4. For an even number of observations, calculate the median by averaging the two middle numbers.
5. Unlike the mean, which uses all data points, the median only relies on the position of values in a sorted list.

Review Questions

• How do you find the median in a data set with an even number of observations?
• Why might you choose to use the median instead of the mean to describe a data set?
• What steps are necessary to determine the median from a given list of numbers?

Related terms

Mean:

The arithmetic average of a set of numbers, calculated by dividing the sum of all values by their count.

Mode:

The value that appears most frequently in a data set. A set may have one mode, more than one mode, or no mode at all.

Outlier:

A data point that differs significantly from other observations. An outlier can affect measures like mean but not usually medians.