An environmental scientist monitors the turbidity of water, TTT (NTU), and the human population density, PPP (people per km2^22), in the surrounding river basins across six different geographical zones. The results for the six zones are shown in the table below.
| Zone | Alpha | Beta | Gamma | Delta | Epsilon | Zeta |
|---|---|---|---|---|---|---|
| Turbidity, TTT | 2.4 | 5.2 | 8.1 | 12.0 | 15.6 | 19.8 |
| Population Density, PPP | 110 | 450 | 240 | 680 | 1150 | 920 |
(You may use STT=214.21S_{TT} = 214.21STT=214.21, SPP=803083.33S_{PP} = 803083.33SPP=803083.33, STP=11529.83S_{TP} = 11529.83STP=11529.83)
Test, at the 5% level of significance, whether there is evidence of a non-zero correlation between water turbidity and population density using the product moment correlation coefficient (PMCC). State your hypotheses and the critical value used.
Calculate Spearman’s rank correlation coefficient between the rank of water turbidity and the rank of population density.
Test, at the 5% level of significance, whether there is evidence of a positive correlation between water turbidity and population density using Spearman's rank correlation. State your hypotheses and the critical value used.
Practise Edexcel A Level Maths Measuring Correlation with exam-style questions for A Level Maths. 108 questions, matched to the Edexcel A Level Maths (9MA0) 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.
