Information was collected about accidents on the Seapron bypass. It was found that the number of accidents per month could be modelled by a Poisson distribution with mean 2.5 Following some work on the bypass, the numbers of accidents during a series of 3-month periods were recorded. The data were used to test whether or not there was a change in the mean number of accidents per month.
Stating your hypotheses clearly and using a \(5 \%\) level of significance, find the critical region for this test. You should state the probability in each tail.
State P(Type I error) using this test.
Data from the series of 3-month periods are recorded for 2 years.
Find the probability that at least 2 of these 3-month periods give a significant result.
Given that the number of accidents per month on the bypass, after the work is completed, is actually 2.1 per month,