CAIE S2 2019 June — Question 7

Exam BoardCAIE
ModuleS2 (Statistics 2)
Year2019
SessionJune
TopicPoisson Distribution
TypeStandard Poisson approximation to binomial

7 Each day at a certain doctor's surgery there are 70 appointments available in the morning and 60 in the afternoon. All the appointments are filled every day. The probability that any patient misses a particular morning appointment is 0.04 , and the probability that any patient misses a particular afternoon appointment is 0.05 . All missed appointments are independent of each other. Use suitable approximating distributions to answer the following.
  1. Find the probability that on a randomly chosen morning there are at least 3 missed appointments.
  2. Find the probability that on a randomly chosen day there are a total of exactly 6 missed appointments.
  3. Find the probability that in a randomly chosen 10-day period there are more than 50 missed appointments.