GCSE Secondary Maths Age 13-17 - Probability & Statistics: Scatter Diagram - Explained

The video tutorial discusses a survey that recorded outside temperatures and electricity usage for heating in 10 homes. It evaluates Molly's claim that electricity usage decreases by 4 units per degree Celsius increase in temperature. The instructor demonstrates how to draw a line of best fit and calculate its gradient, concluding that the decrease is 2.4 units, not 4. The tutorial also explains why the line of best fit should not be used to predict electricity usage at 30 degrees Celsius, as it falls outside the data range.

Why is it inappropriate to use the line of best fit to predict electricity usage at 30 degrees Celsius?

Discuss the importance of using the correct data range when making predictions based on a line of best fit.