CAIE S2 2012 November — Question 6

Exam BoardCAIE
ModuleS2 (Statistics 2)
Year2012
SessionNovember
TopicHypothesis test of a normal distribution

6 In order to obtain a random sample of people who live in her town, Jane chooses people at random from the telephone directory for her town.
  1. Give a reason why Jane's method will not give a random sample of people who live in the town. Jane now uses a valid method to choose a random sample of 200 people from her town and finds that 38 live in apartments.
  2. Calculate an approximate \(99 \%\) confidence interval for the proportion of all people in Jane's town who live in apartments.
  3. Jane uses the same sample to give a confidence interval of width 0.1 for this proportion. This interval is an \(x \%\) confidence interval. Find the value of \(x\).