Question 1
Paper 2Easy5 marksA delivery service compares the delivery times for two routes. The values below summarize the box-and-whisker plots for each route. All values are in minutes.
| Route | Lower whisker end | Lower quartile | Median | Upper quartile | Upper whisker end |
|---|---|---|---|---|---|
| A | 12 | 18 | 24 | 30 | 36 |
| B | 10 | 15 | 20 | 28 | 40 |
(a)[2]
Calculate the interquartile range for each route.
(b)[1]
State which route has the higher median delivery time.
(c)[2]
State which route’s delivery times may be normally distributed. Give a reason based on the symmetry of its box and whiskers.