The times taken by 12 athletes to run 400 m are given in the table below.
| Athlete | A | B | C | D | E | F | G | H | I | J | K | L |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Time (s) | 45.2 | 46.9 | 46.1 | 46.2 | 45.4 | 45.1 | 47.8 | 45.4 | 45.5 | 46.1 | 46.4 | 45.7 |
Find the mean time taken.
Find the standard deviation of these times.
Find the median, the lower quartile and the upper quartile of these times.
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.