Nadia uses the AQA Large Data Set to investigate the relationship between a car's CO emission and its CO2 _2\,2 emission. She finds strong positive correlation and writes:
"For cars in England, CO emissions rise as CO2 _2\,2 emissions rise."
Using your knowledge of the Large Data Set, give two reasons why Nadia's statement is not justified.
Nadia had to leave some cars out of her scatter diagram. Give a reason why.
State one change Nadia could make to her scatter diagram to make it more informative, and give a reason.
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.