The distances travelled, to the nearest kilometre, by 120 commuters are summarised in the table below.
| Distance (km) | 1–5 | 6–10 | 11–20 | 21–40 |
|---|---|---|---|---|
| Frequency | 18 | 30 | 42 | 30 |
Estimate the number of these commuters who travelled less than 15 km.
Explain why your answer to part (a) is only an estimate.
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.