13%
Grouped data does not allow people to find an exact value for the median, but people can determine which class contains the median.
There are 24 times (frequency), so find the class that contains the value: `(24 + 1)/2 = 25/2 = 12.5`.
The median is within the 19 to 22.99 class.
| Time (in seconds) | Frequency f | Cumulative Frequency cf |
| 15–18.99 | 7 | 7 |
| 19–22.99 | 6 | 13 |
| 23–26.99 | 3 | 16 |
| 27–30.99 | 3 | 19 |
| 31–34.99 | 5 | 24 |
| Total | `Σf = 24` |
13%