Quartiles are the values that divide a list of numbers into quarters. To separate values into quartiles, begin by putting the list of numbers in order. Then cut the list into four equal parts.
The quartiles are at the "cuts", as shown in the example below.
So for our example, we can say that:Example: 6, 8, 4, 4, 7, 3, 5
Put in order from lowest to highest: 3, 4, 4, 5, 6, 7, 8
Then cut the list into four equal parts:
- Quartile 1 (Q1) = 4
- Quartile 2 (Q2) = 5 (note this is also the median!)
- Quartile 3 (Q3) = 7