5.1 Drawing line graphs

Drawing a line graph is very similar to drawing a bar chart, and they have many of the same features.

Line graphs need:

• a title
• a label for the vertical axis (e.g. units of currency)
• a numbered scale on the vertical axis
• a label on the horizontal axis (e.g. month) so that it is clear to the reader what they are looking at.

The main difference when drawing a line graph rather than a bar chart, is that rather than a bar, you put a dot or a small cross to represent each piece of information. You then join each dot together with a line. There is significant debate over whether the dots should be joined with a curve or with straight line. Whilst the issue is (believe it or not!) hotly contested, the general consensus seems to be that dots should be joined with straight lines.

Activity 9: drawing line graphs

Timing: 15 minutes

Have a go at drawing line graphs to represent the data below.

1. The table below shows the temperatures in Portstewart during the first two weeks of July 2018.

Table 10

Date	Temperature High ˚C	Temperature Low ˚C
01/07/2018	25	15
02/07/2018	28	17
03/07/2018	29	12
04/07/2018	24	15
05/07/2018	26	13
06/07/2018	22	12
07/07/2018	23	12
08/07/2018	27	12
09/07/2018	26	14
10/07/2018	24	14
11/07/2018	22	14
12/07/2018	22	7
13/07/2018	24	12
14/07/2018	25	20

2. A clothing store has outlets in Bangor and Newry. Use the data in the table below to draw a line graph comparing monthly sales between January and June.

Table 11

Month		Jan	Feb	Mar	Apr	May	Jun
Sales (£000s)	Bangor	29	15	19	20	23	24
	Newry	25	10	16	16	21	26

Answer

Click or tap the graphs below to check your answers.

A line graph with the title ‘Temperatures in Portstewart, Northern Ireland in July 2018’.

Figure 21 A line graph showing half-year sales for Bangor and Newry.