7. The numbers of deaths from pneumoconiosis and lung cancer in a developing country are given in the table.
| Age group (years) | 20-29 | 30-39 | 40-49 | 50-59 | 60-69 | 70 and over |
| Deaths from pneumoconiosis (1000s) | 12.5 | 5.9 | 18.5 | 19.4 | 31.2 | 31.0 |
| Deaths from lung cancer (1000s) | 3.7 | 9.0 | 10.2 | 19.0 | 13.0 | 18.0 |
The correlation between the number of deaths in the different age groups for each disease is to be investigated.
- Give one reason why Spearman's rank correlation coefficient should be used.
- Calculate Spearman's rank correlation coefficient for these data.
- Use a suitable test, at the \(5 \%\) significance level, to interpret your result. State your hypotheses clearly.
(5)