# Learn R: Quartiles, Quantiles, and Interquartile Range

In this course, you will learn how to calculate three important descriptive statistics that describe the spread of the data.

Start## Key Concepts

Review core concepts you need to learn to master this subject

Quartiles

Quantiles

Quantiles and Groups

Median in Quantiles

Interquartile Range Definition

Interquartile Range and Outliers

Quartiles

Quartiles

The three dividing points (or quantiles) that split data into four equally sized groups are called quartiles. For example, in the figure, the three dividing points Q1, Q2, Q3 are quartiles.

Quartiles

Lesson 1 of 3

- 2We’ll come back to the music dataset in a bit, but let’s first practice on a small dataset. Let’s begin by finding the second quartile (Q2). Q2 happens to be exactly the median . Half of the dat…
- 4You just learned a commonly used method to calculate the quartiles of a dataset. However, there is another method that is equally accepted that results in different values! Note that there is no …
- 5We were able to find quartiles manually by looking at the dataset and finding the correct division points. But that gets much harder when the dataset starts to get bigger. Luckily, there is a funct…
- 6Great work! You now know how to calculate the quartiles of any dataset by hand and with R. Quartiles are some of the most commonly used descriptive statistics. For example, You might see schools …

## What you'll create

Portfolio projects that showcase your new skills

## How you'll master it

Stress-test your knowledge with quizzes that help commit syntax to memory