A marine biologist is investigating the relationship between the depth $D$ (in metres) of a coral reef and the condition score $S\,$ of the coral (ranked from 1 to 7, where 7 is the most degraded and 1 is the most pristine). She suspects that coral located at greater depths is more prone to degradation. She collects data from 7 different sites, as shown in the table below:


Depth $D$ (m)	4.5	12.8	8.2	22.1	2.3	35.6	17.4
Condition Rank $S$	3	4	2	7	1	6	5

Calculate Spearman's rank correlation coefficient ( $r_s$ ) for these data.

Stating your hypotheses clearly and using a one-tailed test at the 5% level of significance, interpret your coefficient. (The critical value for $n = 7$ at the 5% level is 0.7143).

State a reason why Spearman's rank correlation coefficient might be more appropriate than the product moment correlation coefficient (PMCC) for this specific dataset.


Depth $D$ (m)	4.5	12.8	8.2	22.1	2.3	35.6	17.4
Condition Rank $S$	3	4	2	7	1	6	5

Calculate Spearman's rank correlation coefficient ( $r_s$ ) for these data.

Stating your hypotheses clearly and using a one-tailed test at the 5% level of significance, interpret your coefficient. (The critical value for $n = 7$ at the 5% level is 0.7143).

State a reason why Spearman's rank correlation coefficient might be more appropriate than the product moment correlation coefficient (PMCC) for this specific dataset.

2.5.6 Data presentation and interpretation

Question 83

Markscheme

2.5.6 Data presentation and interpretation

Question 83

Markscheme

2.5.6 Data presentation and interpretation

Question 83

2.5.6 Data presentation and interpretation Questions

2.5.6 Data presentation and interpretation

Question 83

2.5.6 Data presentation and interpretation Questions