Past exam of the mathematics course of the University of Cambridge / 2024 / iii / Paper 207 / 6 / a / v / Solution

The bus may have arrived before observation began or after observation ended. Its compatible event set is $(-\infty ,2)\cup (20,\infty )$, so, with endpoint conventions chosen to match whether arrivals exactly at 2 or 20 would be seen, the contribution isThis is doubly censored data, because neither the side nor the event time is known.