Edexcel S3 2014 June — Question 8

Exam BoardEdexcel
ModuleS3 (Statistics 3)
Year2014
SessionJune
TopicHypothesis test of Pearson’s product-moment correlation coefficient

8. The heights, in metres, and weights, in kilograms, of a random sample of 9 men are shown in the table below
Man\(A\)\(B\)\(C\)\(D\)\(E\)\(F\)\(G\)\(H\)\(I\)
Height \(( x )\)1.681.741.751.761.781.821.841.881.98
Weight \(( y )\)757610077909511096120
  1. Given that \(\mathrm { S } _ { x x } = 0.0632 , \mathrm {~S} _ { y y } = 1957.5556\) and \(\mathrm { S } _ { x y } = 9.3433\) calculate, to 3 decimal places, the product moment correlation coefficient between height and weight for these men.
  2. Use your value of the product moment correlation coefficient to test whether or not there is evidence of a positive correlation between the height and weight of men. Use a \(5 \%\) significance level. State your hypotheses clearly. Peter does not know the heights or weights of the 9 men. He is given photographs of them and asked to put them in order of increasing weight. He puts them in the order $$A C E B G D I F H$$
  3. Find, to 3 decimal places, Spearman's rank correlation coefficient between Peter's order and the actual order.
  4. Use your value of Spearman’s rank correlation coefficient to test for evidence of Peter's ability to correctly order men, by their weight, from their photographs. Use a 5\% significance level and state your hypotheses clearly.