Edexcel S3 2016 June — Question 4

Exam BoardEdexcel
ModuleS3 (Statistics 3)
Year2016
SessionJune
TopicLinear combinations of normal random variables
TypePooled variance estimation

4. A random sample of 60 children and a random sample of 50 adults were taken and each person was given the same task to complete. The table below summarises the times taken, \(t\) seconds, to complete the task.
Mean, \(\overline { \boldsymbol { t } }\)Standard deviation, \(\boldsymbol { s }\)\(\boldsymbol { n }\)
Children61.25.960
Adults59.15.250
  1. Stating your hypotheses clearly, test, at the \(5 \%\) level of significance, whether or not there is evidence that the mean time taken to complete the task by children is greater than the mean time taken by adults.
    (6)
  2. Explain the relevance of the Central Limit Theorem to your calculation in part (a).
  3. State an assumption you have made to carry out the test in part (a).