Main Index> Basic Statistics>Find an interquartile range
In statistics, finding the difference between the biggest and smallest values in the middle fifty percent of data–can be a tricky concept to grasp at first. However, this article breaks it down into a couple of easy steps, so you’ll have the answer in no time!
If you would prefer to view a video on how to find the IQR, click here (opens a new window).
Probability and statistics: Interquartile range (IQR)
- Step 1: Put the numbers in order
- Step 2: Find the median (How to find a median)
- Step 3: Place parentheses around the numbers above and below the median.
- Step 4: Find Q1 and Q3
Q1 can be thought of as a median in the lower half of the data, and Q3 can be thought of as a median for the upper half of data.
(1,2,5,6,7), 9, ( 12,15,18,19,27). Q1=5 and Q3=18.
- Step 5: Subtract Q1 from Q3 to find the interquartile range.
That’s the easy way to find the interquartile range in statistics!
Tips: This article does tell you the steps. However, if you want to find an IQR quickly, check out the interquartile range calculator.
If you have a boxplot, see this article to find the interquartile range.
Have an even set of numbers? How to Find an Interquartile Range, Part 2