Edexcel FS1 AS Specimen — Question 3

Exam BoardEdexcel
ModuleFS1 AS (Further Statistics 1 AS)
SessionSpecimen
TopicPoisson Distribution
TypeJoint probability of separate processes

  1. Two car hire companies hire cars independently of each other.
Car Hire A hires cars at a rate of 2.6 cars per hour.
Car Hire B hires cars at a rate of 1.2 cars per hour.
  1. In a 1 hour period, find the probability that each company hires exactly 2 cars.
  2. In a 1 hour period, find the probability that the total number of cars hired by the two companies is 3
  3. In a 2 hour period, find the probability that the total number of cars hired by the two companies is less than 9 On average, 1 in 250 new cars produced at a factory has a defect.
    In a random sample of 600 new cars produced at the factory,
    1. find the mean of the number of cars with a defect,
    2. find the variance of the number of cars with a defect.
    1. Use a Poisson approximation to find the probability that no more than 4 of the cars in the sample have a defect.
    2. Give a reason to support the use of a Poisson approximation. \section*{Q uestion 3 continued}