OCR S2 2013 June — Question 8

Exam BoardOCR
ModuleS2 (Statistics 2)
Year2013
SessionJune
TopicHypothesis test of binomial distributions
TypeCalculate Type II error probability

8 The random variable \(R\) has the distribution \(\mathrm { B } ( 14 , p )\). A test is carried out at the \(\alpha \%\) significance level of the null hypothesis \(\mathrm { H } _ { 0 } : p = 0.25\), against \(\mathrm { H } _ { 1 } : p > 0.25\).
  1. Given that \(\alpha\) is as close to 5 as possible, find the probability of a Type II error when the true value of \(p\) is 0.4 .
  2. State what happens to the probability of a Type II error as
    (a) \(p\) increases from 0.4,
    (b) \(\alpha\) increases, giving a reason.