CAIE S1 2016 June — Question 2

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2016
SessionJune
TopicApproximating Binomial to Normal Distribution
TypeSingle probability inequality

2 When visiting the dentist the probability of waiting less than 5 minutes is 0.16 , and the probability of waiting less than 10 minutes is 0.88 .
  1. Find the probability of waiting between 5 and 10 minutes. A random sample of 180 people who visit the dentist is chosen.
  2. Use a suitable approximation to find the probability that more than 115 of these people wait between 5 and 10 minutes.