A sports scientist investigated the effect of dietary nitrate supplementation (via concentrated beetroot juice) on muscle recovery times in elite athletes.
Using a sample of 10 professional road cyclists, she measured the time taken (in hours) to return to baseline muscle soreness after a high-intensity 50 km time-trial. In the first condition, cyclists consumed a placebo drink prior to the trial. In the second condition, they consumed the beetroot juice supplement. The recovery times for each athlete under both conditions are presented in the table below:
| Cyclist | Recovery time to baseline soreness (hours) | |
|---|---|---|
| Placebo condition | Beetroot juice condition | |
| A | 48 | 36 |
| B | 52 | 44 |
| C | 60 | 48 |
| D | 45 | 40 |
| E | 38 | 39 |
| F | 50 | 42 |
| G | 42 | 41 |
| H | 55 | 46 |
| I | 49 | 45 |
| J | 51 | 43 |
Explain one advantage of using the standard deviation rather than the variance as a measure of dispersion for the recovery times recorded in this study.
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.