Lesson

Do you recall how to plot points on the Â coordinate planeÂ ?

Plot the point (6,3) onto the number plane.

Worked Solution

Idea summary

The coordinate plane has an x-axis which runs horizontally and a y-axis which runs vertically.

Each coordinate pair has an x-coordinate and a y-coordinate.

This video explains all the important features of a line graph.

A dachshund puppy is weighed every two weeks.

Week | 2 | 4 | 6 | 8 |
---|---|---|---|---|

Weight (kg) | 1 | 4 | 5 | 5 |

a

Construct a line graph of the information given in the table.

Worked Solution

b

How much weight had the puppy gained from week 2 to week 4?

Worked Solution

c

In which weeks did the puppy's weight not change?

A

From week 4 to week 6.

B

From week 6 to week 8.

Worked Solution

Idea summary

Line graphs use connected points plotted in a number plane to show data.

This video shows us how to create a line graph and all the things we should consider.

The price of chocolate bars over a year has been graphed below.

a

What was the lowest price of the chocolate bars?

Worked Solution

b

In which months was the price the lowest?

Worked Solution

c

What was the highest price of the chocolate bars?

Worked Solution

Idea summary

Line graphs are most useful when we want to track the change of something over time. Some things we could use a line graph for include:

rainfall over a period of time

the time the sun rises each day

the value of the Australian dollar compared to the US Dollar, over time