Constructing Bar Graphs


Objectives

After completing this unit, if you are given a table of information that is to be displayed as a bar graph, you should be able to:

Constructing Bar Graphs

Bar graphs are used to help visually represent data so that comparisons and trends will be easier to see. In this section you will learn how to construct bar graphs. We will begin with data presented in a table. (NOTE: The procedure for constructing tables was discussed in the Constructing Tables unit.) We will first outline the elements of a bar graph and then the steps in constructing bar graphs.

Steps for Constructing a Bar Graph

Below are the steps to following when constructing a bar graph:

  1. Determine the following elements of the bar graph from the table
  2. Draw a set of axes that you will use to construct your graph
  3. Use the data from the table to draw in the bars on the graph.

Now let's go through the process of constructing a bar graph using the table titled Student Housing at Union University.

Student Housing at Union University
Type of Housing Number of Students
Residence Halls

3995
Fraternity/Sorority Houses

985
Off Campus Aparments

2347
Off Campus Houses

1093

  1. Determine the following elements of the bar graph
      • Grouped Data Axis Label--This is the axis that contains the groups. In this case it's the Type of Housing.
      • Frequency Axis Label --This is the axis that contains the frequency counts. In this case it's the Number of Students.
  2. Draw a set of axes that will you will use to construct your graph
  3. Use the data from the table to draw in the bars on the graph
    Once we have the axes constructed, we are ready to draw in the bars. Using the data from the table, draw in the bars to their appropriate height. Keep in mind that this is somewhat of an approximation since the scale does not make drawing exact heights possible.

    Student Housing at Union University

While tables are more exact in their presentation of data, they do not allow the quick visual view of the data. Bar graphs provide one way to present data so that we can get an overview at a glance. In the following practice you will construct a bar graph. While you are doing this, think about the advantages and disadvantages of both representations of data. (Comparison of the different types of visual displays will be outlined in the last instructional unit of this book.)


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