Sam uses the AQA Large Data Set to fit a single regression line to all the cars in it. He obtains
c=0.01+0.0025ec = 0.01 + 0.0025ec=0.01+0.0025e
where c c\,c is the CO emission in g/km and e e\,e is the CO2 _2\,2 emission in g/km.
Use Sam's line to estimate the CO emission of a car whose CO2 _2\,2 emission is 200 g/km.
Explain, using your knowledge of the Large Data Set, why your answer to part (a) cannot be correct for a diesel car.
State the feature of the data that makes fitting a single line to all the cars inappropriate.
Give one reason why Sam's line should not be used for cars in Scotland.
157 exam-style questions on AQA A Level Maths 2.2.2 Scatter diagrams and correlation. Each one has a worked solution and a mark scheme showing where the marks go.