3. Cars arrive at random at a toll bridge at a mean rate of 15 per hour.
- Explain briefly why the Poisson distribution could be used to model the number of cars arriving in a particular time interval.
- Phil stands at the bridge for 20 minutes. Determine the probability that he sees exactly 6 cars arrive.
- Using the statistical tables provided, find the time interval (in minutes) for which the probability of more than 10 cars arriving is approximately 0.3 .