What is extrapolation?
In GCSE Maths, extrapolation means extending a line of best fit on a scatter graph beyond the region of points plotted on the scatter graph, then using the extended line of best fit to predict values. It should not be confused with interpolation, which is using the line of best fit to predict values within the regions of points plotted on the scatter graph.

Extrapolation is often unreliable, as you don’t know if the linear relationship between the two variables will continue beyond the set of data given. The further you extrapolate, the less reliable the estimates become!
Extrapolation revision resources to ace your exams
Extrapolation is covered in our revision notes on scatter graphs from GCSE Maths. You can also have a go at our related exam questions and flashcards to test your understanding. Don’t forget to check out the past papers for more general exam revision.
Need help reaching your target grade? Explore our notes, questions by topic and worked solutions, tailor-made for GCSE Maths.
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