A marine biologist is investigating the relationship between water depth and the concentration of a particular micro-organism. Data were collected from 8 different sites, as shown in the table below.
| Site | A | B | C | D | E | F | G | H |
|---|---|---|---|---|---|---|---|---|
| Depth (h h\,h m) | 120 | 50 | 250 | 180 | 300 | 100 | 220 | 80 |
| Concentration (C C\,C units/ml) | 3.8 | 2.9 | 6.4 | 7.5 | 9.8 | 4.2 | 6.1 | 2.5 |
Calculate Spearman's rank correlation coefficient for these data.
Stating your hypotheses clearly, test at the 5% level of significance whether there is evidence of a positive correlation between water depth and micro-organism concentration.
278 exam-style questions on CCEA A Level Maths 2.5 Data presentation and interpretation, covering 2.5.1 Data presentation and interpretation, 2.5.2 Data presentation and interpretation, 2.5.3 Data presentation and interpretation, 2.5.4 Data presentation and interpretation, 2.5.5 Data presentation and interpretation, 2.5.6 Data presentation and interpretation, 2.5.7 Data presentation and interpretation, 2.5.8 Data presentation and interpretation, 2.5.9 Data presentation and interpretation, and 2.5 Data presentation and interpretation. Each one has a worked solution and a mark scheme showing where the marks go.