OCR S2 — Question 4

Exam BoardOCR
ModuleS2 (Statistics 2)
TopicApproximating Binomial to Normal Distribution
TypePoisson approximation to binomial

4 DVD players are tested after manufacture. The probability that a randomly chosen DVD player is defective is 0.02 . The number of defective players in a random sample of size 80 is denoted by \(R\).
  1. Use an appropriate approximation to find \(\mathrm { P } ( R \geqslant 2 )\).
  2. Find the smallest value of \(r\) for which \(\mathrm { P } ( R \geqslant r ) < 0.01\).