Edexcel S2 2004 June — Question 6

Exam BoardEdexcel
ModuleS2 (Statistics 2)
Year2004
SessionJune
TopicPoisson Distribution
TypeExplain or apply conditions in context

6. Minor defects occur in a particular make of carpet at a mean rate of 0.05 per \(\mathrm { m } ^ { 2 }\).
  1. Suggest a suitable model for the distribution of the number of defects in this make of carpet. Give a reason for your answer. A carpet fitter has a contract to fit this carpet in a small hotel. The hotel foyer requires \(30 \mathrm {~m} ^ { 2 }\) of this carpet. Find the probability that the foyer carpet contains
  2. exactly 2 defects,
  3. more than 5 defects. The carpet fitter orders a total of \(355 \mathrm {~m} ^ { 2 }\) of the carpet for the whole hotel.
  4. Using a suitable approximation, find the probability that this total area of carpet contains 22 or more defects.
    (6)