大象传媒

Bar charts

A bar chart, like a , shows the frequency of events occurring. The height of the bar is the frequency.

A simple bar chart may look like this.

Number of customers vs frequency bar chart

Comparative bar charts

Bar charts may be needed to compare data.

The following frequency table shows the information for the numbers of pets owned by a class.

No pets1 pet2 pets3 or more pets
Boys2423
Girls3321
Boys
No pets2
1 pet4
2 pets2
3 or more pets3
Girls
No pets3
1 pet3
2 pets2
3 or more pets1

A comparative bar chart can show this information. A key that shows which bar represents which data is necessary to be able to read the bar chart properly.

Number of pets owned vs frequency bar chart