For an extract of 150 petrol cars from the Large Data Set, the CO emission x x\,x g/km of each car is recorded. It is given that
∑x=36\sum x = 36∑x=36 and ∑x2=9.6\sum x^2 = 9.6∑x2=9.6
For an extract of diesel cars from the same data set, the mean CO emission is 0.15 g/km and the standard deviation is 0.05 g/km.
Calculate the mean CO emission of the 150 petrol cars.
Calculate the standard deviation of the CO emissions of the 150 petrol cars.
Compare the CO emissions of the petrol cars and the diesel cars in these two extracts.
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.