How_To_Be_Good_At_Math

290 STATISTICS •^ DRAWING LINE GRAPHS

Drawing line graphs

A pencil, ruler, graph paper, and some data are all that’s needed to

draw a line graph. We plot data on the graph, usually as crosses.

Then we join up the crosses to create a continuous line.

First, we need to draw our x

and y axes. Time always

goes along the horizontal x axis

of a line graph. We mark and

write the hours of the day along

this axis, starting with 0800.

Temperature goes along the

vertical y axis. We need to

add a scale that covers the

highest and lowest values in the

table (the range). A scale from

0 to 18°C works well. Let’s mark

every two degrees, otherwise

the scale will look too crowded.

We’ll label the horizontal

x axis “Time” and the

vertical y axis “Temperature (°C)”.

We’ll use special graph

paper marked with small

squares. It will help us to plot

data and draw lines accurately.

Graph paper

A class of school children

recorded the outside

temperature every hour as part

of a science experiment. Let’s

use the data from this table to

draw a line graph.

The x axis is

marked with the

hours of the day

Hour marks

are 10 small

squares apart

10 small squares

represent a rise of 2°C

The y axis is marked

with temperature in

degrees Celsius (°C)

The numbers in this

column show the

temperature at each hour

Hourly temperatures

Time Temperature (°C)

0800

0900

1000

1100

1200

1300

1400

1500

1600

6

8

9

11

12

15

16

15

13

TEMPERATURE (°C)

18

16

14

12

10

8

6

4

2

0

TIME

08000900 1000 1100 1200 1300 1400 1500 1600

290_291_Drawing_line_graphs.indd 290 29/02/2016 18:06