8 In an experiment to investigate the effect of background music in carrying out work, ten students were each given a task. Five of the students did the task in silence and the other five did the task with background music. The scores on the tasks were as follows.
| Silence | 43 | 46 | 55 | 58 | 61 |
| Background music | 19 | 31 | 38 | 52 | 70 |
- Use a Wilcoxon rank-sum test to test at the 10\% level whether the presence of background music affects scores.
- A statistician suggests that the experiment is redesigned so that each student takes one task in silence and another task with background music. The differences in the test scores would then be analysed using a paired-sample method. State an advantage in redesigning the experiment in this way.