Median - JSS3 Mathematics Lesson Note
The median is the middle value in a data set when the values are arranged in ascending or descending order. If there is an odd number of observations, the median is the middle value. If there is an even number of observations, the median is the average of the two middle values.
Example:
Consider the data set: 5,2,8,3,9,4,7.
Arrange it in ascending order: 2,3,4,5,7,8,9
Since there are 7 numbers (odd), the median is the 4th number, which is 5.