This deep dive covers Drawing Lines of Best Fit within Scatter Graphs for GCSE Mathematics. Revise Scatter Graphs in Statistics for GCSE Mathematics with 14 exam-style questions and 20 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 5 of 7 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 5 of 7
Practice
14 questions
Recall
20 flashcards
Drawing Lines of Best Fit
Method for Drawing the Line
- Plot all points accurately on the graph
- Ignore outliers when considering the trend
- Draw a straight line that best represents the trend
- Balance the line so roughly equal numbers of points are above and below
- Make the line long enough to be useful for predictions
Using Lines of Best Fit for Predictions
Interpolation
Predicting values within the range of your data.
Example: If the line shows that 5 hours study gives 75% score, this is interpolation.
Extrapolation
Predicting values outside the range of your data.
Example: Using the line to predict what score someone would get with 12 hours study (if your data only goes up to 10 hours).
Warning: Extrapolation is less reliable - relationships may change outside the measured range.