Complete Table 2 and calculate the Mann-Whitney U U\,U value for the results of Dr Aris's investigation.
Use the following formulas for the Mann-Whitney U U\,U test:
Ua=nanb+na(na+1)2−Ra U_a = n_a n_b + \frac{n_a(n_a + 1)}{2} - R_a Ua=nanb+2na(na+1)−Ra Ub=nanb+nb(nb+1)2−Rb U_b = n_a n_b + \frac{n_b(n_b + 1)}{2} - R_b Ub=nanb+2nb(nb+1)−Rbwhere:
Table 2:
| Condition A: No blue-light exposure | Condition B: Blue-light exposure | ||
|---|---|---|---|
| Coordination score (out of 20) | Rank | Coordination score (out of 20) | Rank |
| 19 | 18 | 18 | 16.5 |
| 18 | 16.5 | 11 | 8.5 |
| 17 | 15 | 10 | 7 |
| 16 | 13.5 | 8 | 5.5 |
| 14 | 11.5 | 8 | 5.5 |
| 16 | 13.5 | 7 | 4 |
| 13 | 10 | 6 | 3 |
| 14 | 11.5 | 5 | 2 |
| 11 | 8.5 | 3 | 1 |
| Total | Total |
Practise Edexcel A Level Psychology Methods with exam-style questions for A Level Psychology. 100 questions, matched to the Edexcel A Level Psychology (9PS0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.