9709 P6 - Nov 2007 - Q5
2480
The arrival times of 204 trains were noted and the number of minutes, t, that each train was late was recorded. The results are summarised in the table.
| Number of minutes late (t) | -2 ≤ t < 0 | 0 ≤ t < 2 | 2 ≤ t < 4 | 4 ≤ t < 6 | 6 ≤ t < 10 |
|---|---|---|---|---|---|
| Number of trains | 43 | 51 | 69 | 22 | 19 |
- Explain what -2 ≤ t < 0 means about the arrival times of trains.
- Draw a cumulative frequency graph, and from it estimate the median and the interquartile range of the number of minutes late of these trains.
