Constructing Bar Graphs

A bar graph uses proportional vertical or horizontal bars to represent the frequency of categorical data.  This allows for the quick comparison of different categories of data.  A common variation of a bar graph is the Pareto graph, which sorts the bars from tallest to shortest.

Bar Graphs

Bar graphs are a powerful tool to visually compare categories of data. To understand how they work, let us explore an example that demonstrates the process of creating a bar graph using our Bar and Pie Chart Generator Tool.

A survey of 100 people was conducted to determine their favorite fast food restaurant among various national brands. The results are summarized in the table below. Using the data, create a bar graph to represent the distribution of responses.

Favorite Restaurants
Response from Survey
Chick-fil-A McDonald's Domino's Taco Bell McDonald's McDonald's McDonald's Chick-fil-A
Wendy's Burger King Burger King Domino's McDonald's Subway Subway KFC
KFC Domino's Chipotle Domino's Chipotle Domino's Taco Bell Wendy's
Chipotle Burger King Pizza Hut Wendy's Taco Bell Domino's KFC Domino's
Chipotle Burger King Chipotle Wendy's Domino's KFC Domino's KFC
Subway Chipotle Burger King Subway Wendy's Burger King KFC Wendy's
McDonald's Chick-fil-A McDonald's Chick-fil-A Subway Domino's Wendy's Subway
Burger King McDonald's Burger King McDonald's Burger King Burger King Subway Wendy's
Pizza Hut Taco Bell Burger King Taco Bell Chipotle Pizza Hut Wendy's KFC
Subway Subway KFC Taco Bell Chick-fil-A Subway Subway Chipotle
Taco Bell Domino's Chipotle Chipotle Burger King Wendy's Wendy's Taco Bell
Wendy's McDonald's Pizza Hut Wendy's McDonald's Taco Bell Burger King Subway
Domino's Taco Bell Domino's McDonald's

Solution

Copy the data to the clipboard, and load it into the Bar and Pie Chart Generator Tool. The tool should automatically generate the bar graph by default since the data is located in column A. If you load a data set where your information is not in A, you will have to change the drop box to the appropriate column.

A bar graph of the survey data on favorite fast food restaurant.

Just add in your title and labels, and you are done.  I left the \(x-axis\) label blank in my example since it is clear all the bars are food food restaurants.

The title and y-axis have been labeled. The x-axis label was removed.

Note

For this tool, I have enabled pan and zoom since labels on the \(x\)-axis can be bunched together and hard to read.  This is something I plan to fix in the future.  For now, you can use your mouse, touch pad, or fingers to change the size of the graph.

$$\tag*{\(\blacksquare\)}$$

Pareto Graphs

While standard bar graphs are effective at showcasing categorical data, there are scenarios where sorting the bars in descending order provides greater clarity. This leads us to a specialized variation of the bar graph known as the Pareto graph.  Let's modify so that all the bars are sorted from largest to smallest..

Example 2

Create a Pareto graph of the preferred fast food restaurants from .

Solution

Here is our result from .

The title and y-axis have been labeled. The x-axis label was removed.

Notice there is a checkbox next to Bar Graph Checkbox that says Pareto. Click on this box, and it will sort the bars for you.

The Pareto box has been check, and the bars are now sorted from longest to shortest.

Notice that is is now easier to see that, in this sample, the most popular restaurants are Wendy's, Domino's,a nd Burger King, and the least popular are KFC, Chick-fil-A, and Pizza Hunt.

$$\tag*{\(\blacksquare\)}$$