Question 1
Paper 1Easy6 marksA transport operator records the journey times, in minutes, for 40 journeys on each of two bus services. The five-number summaries are shown below. No outliers were identified in either sample.
| Service | Minimum | Lower quartile | Median | Upper quartile | Maximum |
|---|---|---|---|---|---|
| A | 12 | 20 | 28 | 36 | 44 |
| B | 8 | 16 | 24 | 32 | 56 |
(a)[5]
On a common horizontal scale from 0 to 60 minutes, construct box-and-whisker diagrams for the two services.
(b)[1]
State which service’s journey-time distribution may be normally distributed, giving a reason based on the symmetry of its box and whiskers.