CAIE S2 2017 June — Question 6

Exam BoardCAIE
ModuleS2 (Statistics 2)
Year2017
SessionJune
TopicHypothesis test of a Poisson distribution

6 The number of sports injuries per month at a certain college has a Poisson distribution. In the past the mean has been 1.1 injuries per month. The principal recently introduced new safety guidelines and she decides to test, at the \(2 \%\) significance level, whether the mean number of sports injuries has been reduced. She notes the number of sports injuries during a 6-month period.
  1. Find the critical region for the test and state the probability of a Type I error.
  2. State what is meant by a Type I error in this context.
  3. During the 6 -month period there are a total of 2 sports injuries. Carry out the test.
  4. Assuming that the mean remains 1.1 , calculate the probability that there will be fewer than 30 sports injuries during a 36-month period.