Keeping it real

Find practical examples of direct proportion.

Research online and think about situations that you know. Here are some ideas to get you started:

• Investigate the way that the variable cost of baby products can relate to the expenses of a family.

• Research the way that prices change over time on the Australian Bureau of Statistics website. Some prices change in direct proportion. Can you find some examples?

• Type ‘currency conversion graph’ into an image search engine such as Google images.

For at least two of the practical examples you find, draw or find a graph that represents the relationship. Explain a practical situation in which the graph would be useful, and explain how the graph would be used in that situation.