OCR S2 2013 January — Question 3

Exam BoardOCR
ModuleS2 (Statistics 2)
Year2013
SessionJanuary
TopicApproximating Binomial to Normal Distribution
TypeSingle probability inequality

3 A factory produces 9000 music DVDs each day. A random sample of 100 such DVDs is obtained.
  1. Explain how to obtain this sample using random numbers.
  2. Given that \(24 \%\) of the DVDs produced by the factory are classical, use a suitable approximation to find the probability that, in the sample of 100 DVDs, fewer than 20 are classical.