After analysis of the data on marine ecosystems, a biologist obtained a calculated value of rs=−0.554r_s = -0.554rs=−0.554 for the relationship between water depth (meters) and the concentration of dissolved organic carbon (mg/L).
Using the information in Table 2 below, what conclusion can the biologist draw about the relationship between water depth and the concentration of dissolved organic carbon? Explain your answer.
| Level of significance for a two-tailed test | |||||
|---|---|---|---|---|---|
| 0.10 | 0.05 | 0.02 | 0.01 | ||
| Level of significance for a one-tailed test | |||||
| 0.05 | 0.025 | 0.01 | 0.005 | ||
| N = | 14 | 0.464 | 0.538 | 0.626 | 0.685 |
| 15 | 0.446 | 0.521 | 0.604 | 0.665 | |
| 16 | 0.429 | 0.503 | 0.582 | 0.641 |
Note: The absolute calculated value of rs r_s\,rs must EQUAL or EXCEED the critical value for significance at the level shown. The biologist used a non-directional (two-tailed) hypothesis with N=15N = 15N=15 and selected a significance level of p≤0.05p \le 0.05p≤0.05.
121 exam-style questions on AQA A Level Psychology Inferential testing (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.