A sports scientist investigated the effect of altitude training on resting heart rate using a repeated measures design with 13 athletes. To analyse the differences in heart rates before and after the training, they conducted a Wilcoxon Signed-Ranks test. One athlete's heart rate was identical in both conditions (difference = 0) and their data was omitted from the analysis, leaving N=12N = 12N=12.
The scientist hypothesised that altitude training would significantly decrease resting heart rate. Therefore, a directional (one-tailed) test was used at the 0.05 (5%) level of significance.
Using the table of critical values below, state the critical value for this test and explain how you located it.
| NNN | One-tailed, p≤0.05p \le 0.05p≤0.05 | Two-tailed, p≤0.05p \le 0.05p≤0.05 |
|---|---|---|
| 8 | 5 | 3 |
| 9 | 8 | 5 |
| 10 | 10 | 8 |
| 11 | 13 | 10 |
| 12 | 17 | 13 |
| 13 | 21 | 17 |
| 14 | 25 | 21 |
| 15 | 30 | 25 |
513 exam-style questions on OCR A Level Psychology Data recording, analysis and presentation. Each one has a worked solution and a mark scheme showing where the marks go.