OCR Further Statistics 2018 March — Question 8

Exam BoardOCR
ModuleFurther Statistics (Further Statistics)
Year2018
SessionMarch
TopicHypothesis test of Spearman’s rank correlation coefficien

8 At a wine-tasting competition, two judges give marks out of 100 to 7 wines as follows.
Wine\(A\)\(B\)\(C\)\(D\)\(E\)\(F\)\(G\)
Judge I86.387.587.688.889.489.990.5
Judge II85.388.182.787.789.089.491.5
  1. A spectator claims that there is a high level of agreement between the rank orders of the marks given by the two judges. Test the spectator's claim at the \(1 \%\) significance level.
  2. A competitor ranks the wines in a random order. The value of Spearman's rank correlation coefficient between the competitor and Judge I is \(r _ { s }\).
    (a) Find the probability that \(r _ { s } = 1\).
    (b) Show that \(r _ { s }\) cannot take the value \(\frac { 55 } { 56 }\).