Vocabulary

Box Plot: a graph that uses a number line to show the distribution of a set of data using the median, quartiles, and extreme values.

Minimum Value: the lowest extreme value which is the far left “whisker” of the graph.

Maximum Value: the highest extreme value which is the far-right “whisker” of the graph.

1st Quartile: the far-left value of the box.

Median: the center value of the graph shown by a vertical line in the box.

3rd Quartile: the far-right value of the box.

Range: the difference between the maximum and minimum value.

Interquartile range: the difference between the 3rd and 1st quartile.

Concepts

Analyzing box plots for critical information.

Rules

Use the above definitions to find the required information.

Example

For the box plot below, what are the minimum and maximum values?

Solution

The endpoints of the whiskers define the minimum and maximum values of the data. So, the data in the plot has a minimum of 50 and a maximum of 80.

Pre-requisite Skills

Line Plots (6.2.6)

Find Mean, Median, Mode and, Range Using Graphs (6.2.9)