7. Nathan believes that shearers from Wales can shear more sheep, on average, in a given time than shearers from New Zealand. He takes a random sample of 8 shearers from Wales and 7 shearers from New Zealand. The numbers below indicate how many sheep were sheared in 45 minutes by the 15 shearers.
| Wales: | 60 | 53 | 42 | 38 | 37 | 36 | 31 | 28 |
| New Zealand: | 39 | 35 | 27 | 26 | 17 | 16 | 15 | |
Use a Mann-Whitney U test at the \(1 \%\) significance level to test whether Nathan is correct. You must state your hypotheses clearly and state the critical region.