GB-32-04-001 · Scatter graphs and extrapolation
A scatter graph uses data for temperatures from 9°C to 30°C and shows negative correlation with heating cost. Explain why using a line of best fit to predict the cost at 55°C may be unreliable.
Scatter Graphs: Extrapolation Reliability
Supplementary GCSE method — not covered in this booklet
Method
Predictions outside the range of the given data (extrapolation) are unreliable because the linear trend may not continue
Worked Example (GB-32-04-001)
1)
55°C is outside 9–30°C; the trend may not continue.
Ans =
The prediction extrapolates outside the observed temperature range.