[Exer8-4] Exercise 81 of Book {Devore2017B} P.138
The number of requests for assistance received by a towing service(牵引服务/牽引服務/service de remorquage) is a Poisson process with rate $\alpha=4$ per hour.
- (a) Compute the probability that exactly ten requests are received during a particular $2$-hour period.
- (b) If the operators of the towing services take a $30$-min break for lunch, what is the probability that they do not miss any calls for assistance?
- (c) How many calls would you expect during their break?