The two regression lines below are fitted to an extract from the AQA Large Data Set, where c c\,c is the CO emission in g/km and e e\,e is the CO2 _2\,2 emission in g/km:
diesel cars: c=0.02+0.0009ec = 0.02 + 0.0009ec=0.02+0.0009e
petrol cars: c=−0.18+0.0032ec = -0.18 + 0.0032ec=−0.18+0.0032e
For both fuel types the CO2 _2\,2 emissions in the extract lie between 100 g/km and 245 g/km.
Find the set of values of eee, within the range of the extract, for which the petrol line predicts a CO emission of more than 0.5 g/km.
Show that the diesel line predicts a CO emission of less than 0.5 g/km for every value of e e\,e in the range of the extract.
Explain how part (b) is consistent with a known property of the Large Data Set.
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.