CAIE S1 2006 June — Question 7

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2006
SessionJune
TopicApproximating Binomial to Normal Distribution
TypeCombined binomial and normal events

7 A survey of adults in a certain large town found that \(76 \%\) of people wore a watch on their left wrist, \(15 \%\) wore a watch on their right wrist and \(9 \%\) did not wear a watch.
  1. A random sample of 14 adults was taken. Find the probability that more than 2 adults did not wear a watch.
  2. A random sample of 200 adults was taken. Using a suitable approximation, find the probability that more than 155 wore a watch on their left wrist.