CAIE S2 2018 November — Question 6

Exam BoardCAIE
ModuleS2 (Statistics 2)
Year2018
SessionNovember
TopicHypothesis test of binomial distributions
TypePerform one-tailed hypothesis test

6 In the past, Angus found that his train was late on \(15 \%\) of his daily journeys to work. Following a timetable change, Angus found that out of 60 randomly chosen days, his train was late on 6 days.
  1. Test at the \(10 \%\) significance level whether Angus' train is late less often than it was before the timetable change.
    Angus used his random sample to find an \(\alpha \%\) confidence interval for the proportion of days on which his train is late. The upper limit of his interval was 0.150 , correct to 3 significant figures.
  2. Calculate the value of \(\alpha\) correct to the nearest integer.