OCR S2 2005 June — Question 5

Exam BoardOCR
ModuleS2 (Statistics 2)
Year2005
SessionJune
TopicApproximating Binomial to Normal Distribution
TypeCompare approximation methods

5 The random variable \(W\) has the distribution \(\mathbf { B } ( 30 , p )\).
  1. Use the exact binomial distribution to calculate \(\mathbf { P } ( W = 10 )\) when \(p = 0.4\).
  2. Find the range of values of \(p\) for which you would expect that a normal distribution could be used as an approximation to the distribution of \(W\).
  3. Use a normal approximation to calculate \(\mathrm { P } ( W = 10 )\) when \(p = 0.4\).