http://www.ck12.org Chapter 2. Visualizations of Data
2.3 Box-and-Whisker Plots
Learning Objectives
- Calculate the values of the 5−number summary.
- Draw and translate data sets to and from a box-and-whisker plot.
- Interpret the shape of a box-and-whisker plot.
- Compare distributions of univariate data (shape, center, spread, and outliers).
- Describe the effects of changing units on summary measures.
Introduction
In this section we will round out our investigation of different types of visual displays by introducing the box-and-
whisker plots. The basic ideas of shape, center, spread, and outliers will be investigated in this context and students
will be asked to become proficient in translating and interpreting graphs of univariate data of the various types.
The Five-Number Summary
Thefive-number summaryis a numerical description of a data set comprised of the following measures (in order):
Minimum value, lower quartile, median, upper quartile, maximum value.
In order to review finding these values from Chapter One, let’s turn to another recycling/conservation related issue.
The huge population growth in the western United States in recent years, along with a trend toward less annual
rainfall in many areas and even drought conditions in others, has put tremendous strain on the water resources
available now and the need to protect them in the years to come. Here is a listing of the reservoir capacities of the
major water sources for Arizona:
TABLE2.27:
Lake/Reservoir % of Capacity
Salt River System 59
Lake Pleasant 49
Verde River System 33
San Carlos 9
Lyman Reservoir 3
Show Low Lake 51
Lake Havasu 98