Axes of Information
No, we aren’t talking about tools used to chop wood. Axes is the plural of axis. A bar graph has a vertical axis and a horizontal axis. Each axis contains pertinent information like items to be compared and the data of which the items are compared. Bar graphs are the easiest to glance and glean the information that you need because of the way they are set up. Your eyes can quickly scan the separated bars to see where each bar stops on the graph.
How to Read a Bar Graph
- Read the title of the bar graph. It gives you the overview. Example: Real Estate Sales Volume for December
- Read the titles on both the vertical and horizontal axis so you will know what is being compared. Example: Vertical axis displays Sales Volume in Millions and horizontal axis has agents’ names.
- Determine the unit by which the data is measured. If you see data broken out by 5, 10, 15, 20 etc. that could mean anything from feet to gallons. Hint: You will find the unit being measured in the data title. Example: Sales Volumes in Hundred Thousand Dollars.
- Determine question being asked. Example: Who has the least sales in the office?
- Which bar best correlates with question being asked? Example: For least sales, you would look for the shortest bar on the graph.
Horizontal Bar Graph
Look over the graph below. By the title of the graph, you know the subject of the bar graph is real estate sales volume for the month of December. Look at the vertical axis and you will find the real estate agents whose sales volume we are comparing. The horizontal axis shows us we are measuring the sales volume in hundred thousands so we read the data as $100,000, $200,000, $300,000, etc.
Let’s compare the agents. According to the graph, Christie had the most sales for December with $800,000 in sales and Ronna had the least sales with almost $200,000. Pete had $400,000, Luke had $700,000, and Susan fell a little short of $500,000.
Vertical Bar Graph
The vertical bar graph example presents the same information as the horizontal bar graph example. Expect to see either or both types of bar graphs on the exam.
