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:


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)
Sunday20
Monday12
Tuesday10
Wednesday9
Thursday16
Friday27
Saturday30

Honduras Murder graph

Did You Know That...?

In 2010, Honduras in Central America had almost the highest rate of intentional homicide in the world. There were about 6240 murders. This is approximately 17 murders per day! Sadly, Southern Africa's murder rate was even higher.

Example Two - Best-Selling Musicians of All-Time

NAME OF MUSICIAN
(INDEPENDENT VARIABLE)
NUMBER OF ALBUM SALES
(DEPENDENT VARIABLE)
Beatles600 million
Elvis Presley600 million
Michael Jackson350 million
Led Zeppelin250 million
Queen150 million

Musicians graph

Question - "Hotness" of Hot Peppers

Chili Peppers


NAME OF PEPPER
(INDEPENDENT VARIABLE)
HOTNESS
(DEPENDENT VARIABLE)
Jalapeno3 500
Peter pepper10 000
Tabasco pepper30 000
Bird's eye chilli50 000
Habanero chilli100 000

The table above shows part of the Scoville Scale for the "hotness" of peppers (chillies). The units are Scoville Heat Units (SHU). Draw a column graph of this data. (Hint: Go up by 5000s on the vertical axis.)

Did You Know That...?

On the Scoville Scale, the pepper spray used by police is over 500 000 SHU.