OCR MEI S2 2010 June — Question 1

Exam BoardOCR MEI
ModuleS2 (Statistics 2)
Year2010
SessionJune
TopicHypothesis test of Spearman’s rank correlation coefficien

1 Two celebrities judge a talent contest. Each celebrity gives a score out of 20 to each of a random sample of 8 contestants. The scores, \(x\) and \(y\), given by the celebrities to each contestant are shown below.
ContestantABCDEFGH
\(x\)61792013151114
\(y\)6131011971215
  1. Calculate the value of Spearman's rank correlation coefficient.
  2. Carry out a hypothesis test at the \(5 \%\) significance level to determine whether there is positive association between the scores allocated by the two celebrities.
  3. State the distributional assumption required for a test based on the product moment correlation coefficient. Sketch a scatter diagram of the scores above, and discuss whether it appears that the assumption is likely to be valid.