STATISTICS • BAR CHARTS 285
Bar charts
A bar chart uses bars or columns to represent groups or sets
of data. The size of each bar shows the frequency of the data.
Bar charts are also called bar graphs and column graphs.
To find out how many white
cars were seen, look across
from the top of the White bar to
the vertical axis. Then read the
number (5) off the scale.
We can redraw the same
chart so that the bars are
horizontal, going across the
chart, rather than vertical.
The car colours are
now along the vertical
axis, while the number of
cars (the frequency) can be
read off the horizontal axis.
Let’s look at this bar chart. It
uses data from a survey of
car colours. The bars are all the
same width, separated by gaps.
The chart is framed on two
sides by lines called axes.
The bars for car colours sit on the
horizontal axis. A scale on the
vertical axis shows the number
of cars seen (the frequency).
The height or length
of a bar shows
the frequency.
Vertical
axis
Horizontal axis
The frequency of
white cars is 5
NUMBER OF CARS SEEN
0
1
2
3
4
5
6
7
8
Silver
COLOUR OF CAR
Red Blue White Black
Look along the
horizontal axis to
find the frequency
The scale is now along
the horizontal axis
0 1 2 3 4 5 6 7 8
Black
White
Blue
Red
Silver
Car colours
COLOUR OF CAR
NUMBER OF CARS SEEN
Car colours
284_285_Block_bar_charts.indd 285 29/02/2016 18:06