Tony is investigating the relationship between his daily energy bill in pounds (eee) and the average daily temperature in degrees (ttt) each day in the winter.
He finds that there is a negative correlation between Tony's bill and the average daily temperature, and that for each 1∘C1^\circ\text{C}1∘C increase in temperature Tony's bill decreases by 40p.
When the average daily temperature is 0∘C0^\circ\text{C}0∘C, Tony's daily energy bill is £7.30.
Give an equation for the regression line.
Explain why this model might not be appropriate for Tony's energy bill in the summer.
46 exam-style questions on Edexcel A Level Maths Correlation, covering 4.1 Correlation and 4.2 Linear Regression. Each one has a worked solution and a mark scheme showing where the marks go.