The CO emissions, x x\,x g/km, of 400 cars are summarised in the table below.
| CO emission (g/km) | Frequency |
|---|---|
| 0.0≤x<0.10.0 \le x < 0.10.0≤x<0.1 | 40 |
| 0.1≤x<0.20.1 \le x < 0.20.1≤x<0.2 | 120 |
| 0.2≤x<0.30.2 \le x < 0.30.2≤x<0.3 | 130 |
| 0.3≤x<0.50.3 \le x < 0.50.3≤x<0.5 | 90 |
| 0.5≤x<1.00.5 \le x < 1.00.5≤x<1.0 | 20 |
For this question, a value is defined to be an outlier if it is greater than Q3+1.5(Q3−Q1)Q_3 + 1.5(Q_3 - Q_1)Q3+1.5(Q3−Q1).
Use linear interpolation to estimate the median CO emission.
Use linear interpolation to estimate Q1 Q_1\,Q1 and Q3Q_3Q3, and hence estimate the interquartile range.
Hence determine whether a car with a CO emission of 0.60 g/km would be classed as 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.