The median of a list of data is the middle item in that data when it has been arranged in order of size.

If the list contains an even quantity of data, then the median is the mean average of the middle two values.

For example

the median of the five numbers 3,8,12,13,19 is 12

the median of the five numbers 6,2,9,1,3 is 3 not 9.

the median of the size numbers 1,4,7,9,10,16 is 8, being the mean average of the two middle numbers 7 and 9.

If the list contains an even quantity of data, then the median is the mean average of the middle two values.

For example

the median of the five numbers 3,8,12,13,19 is 12

the median of the five numbers 6,2,9,1,3 is 3 not 9.

the median of the size numbers 1,4,7,9,10,16 is 8, being the mean average of the two middle numbers 7 and 9.

## Software/Applets used on this page

## Glossary

### mean

the sum of all the members of the list divided by the number of items in the list.

### median

the middle value of a set of data that has been arranged in order of magnitude; half the data values are above it and half are below.

### union

The union of two sets A and B is the set containing all the elements of A and B.