CAIE S1 2020 November — Question 4

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2020
SessionNovember
TopicApproximating Binomial to Normal Distribution
TypeCombined binomial and normal events

4 The 1300 train from Jahor to Keman runs every day. The probability that the train arrives late in Keman is 0.35 .
  1. For a random sample of 7 days, find the probability that the train arrives late on fewer than 3 days.
    A random sample of 142 days is taken.
  2. Use an approximation to find the probability that the train arrives late on more than 40 days.