A marine biologist conducted a study to investigate whether there is a positive correlation between sea surface temperature (in degrees Celsius) and the metabolic rate of a certain species of starfish (measured by oxygen consumption in μ \mu\,μl/g/h). A sample of 19 starfish was tested. Because the biologist predicted a positive relationship, a one-tailed test was used.
The calculated value of Spearman's rank correlation coefficient (rsr_srs) was 0.405.
| Level of significance for a one-tailed test | 0.05 | 0.025 |
|---|---|---|
| Level of significance for a two-tailed test | 0.10 | 0.05 |
| N=16N = 16N=16 | .429 | .503 |
| 17 | .414 | .485 |
| 18 | .401 | .472 |
| 19 | .391 | .460 |
| 20 | .380 | .447 |
Note: The calculated value of rs r_s\,rs must be equal to or greater than the critical value for statistical significance to be shown.
Is the biologist's calculated value significant at the p≤0.05 p \le 0.05\,p≤0.05 level? With reference to Table 1, explain your answer.
Practise AQA A Level Psychology Inferential testing (A-level only) with exam-style questions for A Level Psychology. 123 questions, matched to the AQA A Level Psychology (7182) 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.
