For a sample of petrol cars, the mean CO emission is 0.26 g/km and the standard deviation is 0.05 g/km.
For this question, an outlier is defined as a value more than two standard deviations from the mean.
Determine whether a CO emission of 0.38 g/km is an outlier.
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.