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 the equation of the regression line is e=7.3−0.4te = 7.3 - 0.4te=7.3−0.4t
Describe the correlation between Tony's bill and the average daily temperature.
Give an interpretation of the gradient of this regression line.
Explain why this model might not be appropriate for Tony's energy bill in the summer.
244 exam-style questions on AQA A Level Maths 2.2 L: Data presentation and interpretation, covering 2.2.1 Single-variable data diagrams, 2.2.2 Scatter diagrams and correlation, 2.2.3 Central tendency, variation and standard deviation, 2.2.4 Outliers and cleaning data, and 2.2 L: Data presentation and interpretation. Each one has a worked solution and a mark scheme showing where the marks go.