• Read information from a boxplot and make conclusions
• Compare boxplots

Characteristics of a Boxplot

The characteristics of a boxplot include the five-number summary (minimum, Q1, median, Q3, and maximum) together, the interquartile range (IQR), and any outliers.

Minimum and Maximum (and also Median)

Let’s start exploring the idea of the spread of a data set and begin by describing spread through the minimum and maximum of the data set. To find the minimum and maximum values of a data set, find the least and the greatest value in the data set. It might be best to order your data from smallest to the largest because you can also find the measure of center, median, through the ordered data set as well. Recall: The median is the value that splits the data in half.

First Quartile ([latex]Q1[/latex]) and Third Quartile ([latex]Q3[/latex])

[latex]Q1[/latex] and [latex]Q3[/latex]

• The first quartile, also known as [latex]Q1[/latex], can be thought of as the median of the values that lie below the median for the whole data set. It is the [latex]25[/latex]^th percentile of the data set.
• The third quartile, also known as [latex]Q3[/latex], can be thought of as the median of the values that lie above the median for the whole data set. It is the [latex]75[/latex]^th percentile of the data set.

Fun fact: Since the median is the middle value between [latex]Q1[/latex] and [latex]Q3[/latex], the median is also commonly known as the second quartile ([latex]Q2[/latex]).