9231 P41 - Jun 2022 - Q6 - 10 marks
6707
A teacher at a large college gave a mathematical puzzle to all the students. The median time taken by a random sample of 24 students to complete the puzzle was 18.0 minutes. The students were then given practice in solving puzzles. Two weeks later, the students were given another mathematical puzzle of the same type as the first. The times, in minutes, taken by the random sample of 24 students to complete this puzzle are as follows.
| 18.2 | 17.5 | 16.4 | 15.1 | 20.5 | 26.5 | 19.2 | 23.2 |
| 17.9 | 18.8 | 25.8 | 19.9 | 17.7 | 16.2 | 17.3 | 16.6 |
| 17.1 | 20.1 | 20.3 | 12.6 | 16.0 | 21.4 | 22.7 | 18.4 |
The teacher claims that the practice has not made any difference to the average time taken to complete a puzzle of this type.
Carry out a Wilcoxon signed-rank test, at the \(10\%\) significance level, to test whether there is sufficient evidence to reject the teacher's claim.
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