AQA S2 2013 June — Question 2

Exam BoardAQA
ModuleS2 (Statistics 2)
Year2013
SessionJune
TopicChi-squared distribution

2 A town council wanted residents to apply for grants that were available for home insulation. In a trial, a random sample of 200 residents was encouraged, either in a letter or by a phone call, to apply for the grants. The outcomes are shown in the table.
Applied for grantDid not apply for grantTotal
Letter30130160
Phone call142640
Total44156200
  1. The council believed that a phone call was more effective than a letter in encouraging people to apply for a grant. Use a \(\chi ^ { 2 }\)-test to investigate this belief at the \(5 \%\) significance level.
  2. After the trial, all the residents in the town were encouraged, either in a letter or by a phone call, to apply for the grants. It was found that there was no association between the method of encouragement and the outcome. State, with a reason, whether a Type I error, a Type II error or neither occurred in carrying out the test in part (a).
    (2 marks)