2 A large hotel has 90 bedrooms. Sometimes a guest makes a booking for a room, but then does not arrive. This is called a 'no-show'. On average \(10 \%\) of bookings are no-shows. The hotel manager accepts up to 94 bookings before saying that the hotel is full. If at least 4 of these bookings are no-shows then there will be enough rooms for all of the guests. 94 bookings have been made for each night in August. You should assume that all bookings are independent.
- State the distribution of the number of no-shows on one night in August.
- State the conditions under which the use of a Poisson distribution is appropriate as an approximation to a binomial distribution.
- Use a Poisson approximating distribution to find the probability that, on one night in August,
(A) there are exactly 4 no-shows,
(B) there are enough rooms for all of the guests who do arrive. - Find the probability that, on all of the 31 nights in August, there are enough rooms for all of the guests who arrive.
- (A) In August there are \(31 \times 94 = 2914\) bookings altogether. State the exact distribution of the total number of no-shows during August.
(B) Use a suitable approximating distribution to find the probability that there are at most 300 no-shows altogether during August.