CAIE S1 2017 November — Question 5

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2017
SessionNovember
TopicApproximating Binomial to Normal Distribution
TypeCombined binomial and normal events

5 Blank CDs are packed in boxes of 30 . The probability that a blank CD is faulty is 0.04 . A box is rejected if more than 2 of the blank CDs are faulty.
  1. Find the probability that a box is rejected.
  2. 280 boxes are chosen randomly. Use an approximation to find the probability that at least 30 of these boxes are rejected.