Rate of Change (Gradient)
The steepness of the line indicates how fast something is changing:
- Steep upward: Rapid increase
- Gentle upward: Slow increase
- Horizontal: No change
- Steep downward: Rapid decrease
Interpolation vs Extrapolation
- Interpolation: Estimating values between known data points
- Extrapolation: Predicting values beyond the range of data
- Reliability: Interpolation is more reliable than extrapolation
Correlation
When comparing two variables on different line graphs:
- Positive correlation: Both increase together
- Negative correlation: One increases as the other decreases
- No correlation: No clear relationship
This deep dive covers Advanced Line Graph Concepts within Line Graphs for GCSE Mathematics. Revise Line Graphs in Statistics for GCSE Mathematics with 10 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 8 of 10 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Line Graphs
A time series graph is used to show:
A time series graph shows house prices from 2015 to 2023. A student extends the line to predict the house price in 2030. Explain why this prediction might be unreliable.