Ellie investigates the relationship between the fuel economy x x\,x miles per gallon and the CO2 _2\,2 emission y y\,y g/km of 25 petrol cars. She finds that the equation of the regression line of y y\,y on x x\,x is
y=310−3.4xy = 310 - 3.4xy=310−3.4x
Describe the correlation between fuel economy and CO2 _2\,2 emission.
Give an interpretation of the gradient of this regression line.
Explain why this model would not be appropriate for a fully electric car.
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.