6 Each competitor in a lumberjacking competition has to perform various disciplines for which they are timed. A spectator thinks that the times for two of the disciplines, chopping wood and sawing wood, are related. The table and the scatter diagram below show the times of a random sample of 8 competitors in these two disciplines.
| Competitor | A | B | C | D | E | F | G | H |
| Sawing | 17.1 | 16.7 | 14.3 | 14.0 | 12.8 | 21.5 | 15.3 | 14.4 |
| Chopping | 23.5 | 20.6 | 21.9 | 18.8 | 21.5 | 24.8 | 19.7 | 19.3 |
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- The spectator decides to carry out a hypothesis test to investigate whether there is any relationship.
Explain why the spectator decides that a test based on Pearson's product moment correlation coefficient may not be valid.
- Determine the value of Spearman's rank correlation coefficient.
- Carry out a hypothesis test at the \(5 \%\) significance level to investigate whether there is positive association between sawing and chopping times.