Column Graphs

A column graph is a graph with a horizontal axis (the x-axis), a vertical axis (the y-axis) and separated rectangular bars that indicate discrete data.

Of the two variables in bar graphs, the independent variable is the one on which the other variable depends. The independent variable goes on the horizontal axis and a common example is the months of the year. The dependent variable is written on the vertical axis and a common example includes the frequency.

Some important tips are:

• The numbers that are used on the axes should go up by 1s, 2s, 5s, 10s, 20s, 50s, 100s, 200s, 500s, 1000s and so on.
• Never use other numbers such as 3s, 4s, 6s, 7s, 8s and 9s.
• The axes do not have to start at zero.

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Example One - Number of Murders

The number of murders in one week in Honduras, Central America:

WEEK DAY (INDEPENDENT VARIABLE)	NUMBER OF MURDERS (DEPENDENT VARIABLE)
Sunday	20
Monday	12
Tuesday	10
Wednesday	9
Thursday	16
Friday	27
Saturday	30

Example Two - Best-Selling Musicians of All-Time

NAME OF MUSICIAN (INDEPENDENT VARIABLE)	NUMBER OF ALBUM SALES (DEPENDENT VARIABLE)
Beatles	600 million
Elvis Presley	600 million
Michael Jackson	350 million
Led Zeppelin	250 million
Queen	150 million