AQA S3 2012 June — Question 5

Exam BoardAQA
ModuleS3 (Statistics 3)
Year2012
SessionJune
TopicCentral limit theorem
TypeSample size determination

5 A random sample of 125 people was selected from a council's electoral roll. Of these, 68 were in favour of a proposed local building plan.
  1. Construct an approximate 98\% confidence interval for the percentage of people on the council's electoral roll who were in favour of the proposal.
  2. Calculate, to the nearest 5, an estimate of the minimum sample size necessary in order that an approximate \(98 \%\) confidence interval for the percentage of people on the council's electoral roll who were in favour of the proposal has a width of at most 10 per cent.