OCR S1 2005 June — Question 3

Exam BoardOCR
ModuleS1 (Statistics 1)
Year2005
SessionJune
TopicBinomial Distribution
TypeProbability of range of values

3 In a supermarket the proportion of shoppers who buy washing powder is denoted by \(p .16\) shoppers are selected at random.
  1. Given that \(p = 0.35\), use tables to find the probability that the number of shoppers who buy washing powder is
    (a) at least 8,
    (b) between 4 and 9 inclusive.
  2. Given instead that \(p = 0.38\), find the probability that the number of shoppers who buy washing powder is exactly 6 .