Edexcel S2 2014 June — Question 3

Exam BoardEdexcel
ModuleS2 (Statistics 2)
Year2014
SessionJune
TopicPoisson Distribution
TypePoisson with binomial combination

3. Accidents occur randomly at a road junction at a rate of 18 every year. The random variable \(X\) represents the number of accidents at this road junction in the next 6 months.
  1. Write down the distribution of \(X\).
  2. Find \(\mathrm { P } ( X > 7 )\).
  3. Show that the probability of at least one accident in a randomly selected month is 0.777 (correct to 3 decimal places).
  4. Find the probability that there is at least one accident in exactly 4 of the next 6 months.