Edexcel S2 2016 June — Question 1

Exam BoardEdexcel
ModuleS2 (Statistics 2)
Year2016
SessionJune
TopicPoisson Distribution
TypeMean-variance comparison for Poisson validation

  1. A student is investigating the numbers of cherries in a Rays fruit cake. A random sample of Rays fruit cakes is taken and the results are shown in the table below.
Number of cherries012345\(\geqslant 6\)
Frequency24372112420
  1. Calculate the mean and the variance of these data.
  2. Explain why the results in part (a) suggest that a Poisson distribution may be a suitable model for the number of cherries in a Rays fruit cake. The number of cherries in a Rays fruit cake follows a Poisson distribution with mean 1.5 A Rays fruit cake is to be selected at random. Find the probability that it contains
    1. exactly 2 cherries,
    2. at least 1 cherry. Rays fruit cakes are sold in packets of 5
  3. Show that the probability that there are more than 10 cherries, in total, in a randomly selected packet of Rays fruit cakes, is 0.1378 correct to 4 decimal places. Twelve packets of Rays fruit cakes are selected at random.
  4. Find the probability that exactly 3 packets contain more than 10 cherries. \href{http://PhysicsAndMathsTutor.com}{PhysicsAndMathsTutor.com}