Bar Graphs and Pie Charts (Jump to: Lecture | Video )

Bar Graph

A bar graph lists each category on the horizontal axis and the number of occurrences for each category on the vertical axis.

Imagine that you reached into a bag of candy 16 times and pulled out the following colors of candy:

Red, Green, Green, Green, Blue, Blue, Red, Blue, Green, Green, Red, Red, Blue, Green, Red, Red

How could we display this information as a bar graph? First, create a frequency table. Then, use that information to create the bar graph.

Figure 1.

In a bar graph, the bars don't touch. If the bars touched, this would be a histogram.

Pie Chart

A pie chart is a circle divided into sectors, where each sector represents a category of data that is proportional to the total amount of data collected.


A proportion is a part considered in relation to its whole.

For example, imagine a pizza with 8 slices. Your friend takes and eats 3 slices. In this case, 3/8 is the proportion of the pizza your friend took. This can also be represented as a decimal. 3 / 8 = 0.375

Use the information from the "bag of candy" example to contruct a pie chart for the three different colors.

Figure 2.

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