When it comes to statistical types of graphs and charts, the pie chart (or the circle chart) has a crucial place and meaning. It displays data and statistics in an easy-to-understand ‘pie-slice’ format and illustrates numerical proportion.
Each pie slice is relative to the size of a particular category in a given group as a whole. To say it in another way, the pie chart brakes down a group into smaller pieces. It shows part-whole relationships. To make a pie chart, you need a list of categorical variables and numerical variables.
- When you want to create and represent the composition of something.
- It is very useful for displaying nominal or ordinal categories of data.
- To show percentage or proportional data.
- When comparing areas of growth within a business such as profit.
- Pie charts work best for displaying data for 3 to 7 categories.
A histogram shows continuous data in ordered rectangular columns (to understand what is continuous data see our post discrete vs continuous data). Usually, there are no gaps between the columns.
The histogram displays a frequency distribution (shape) of a data set. At first glance, histograms look alike to bar graphs. However, there is a key difference between them. Bar Chart represents categorical data and histogram represent continuous data.
The scatter plot is an X-Y diagram that shows a relationship between two variables. It is used to plot data points on a vertical and a horizontal axis. The purpose is to show how much one variable affects another.