2.2.2 Scatter diagrams and correlation

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Question 105

An environmental scientist monitors the turbidity of water, $T$ (NTU), and the human population density, $P$ (people per km $^2$ ), 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, $T$	2.4	5.2	8.1	12.0	15.6	19.8
Population Density, $P$	110	450	240	680	1150	920

(You may use $S_{TT} = 214.21$ , $S_{PP} = 803083.33$ , $S_{TP} = 11529.83$ )

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.

[4]

Calculate Spearman’s rank correlation coefficient between the rank of water turbidity and the rank of population density.

[3]

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.

[3]

2.2.2 Scatter diagrams and correlation

Question 105

Zone	Alpha	Beta	Gamma	Delta	Epsilon	Zeta
Turbidity, $T$	2.4	5.2	8.1	12.0	15.6	19.8
Population Density, $P$	110	450	240	680	1150	920

(You may use $S_{TT} = 214.21$ , $S_{PP} = 803083.33$ , $S_{TP} = 11529.83$ )

[4]

Calculate Spearman’s rank correlation coefficient between the rank of water turbidity and the rank of population density.

[3]

2.2.2 Scatter diagrams and correlation

Question 105

Markscheme

2.2.2 Scatter diagrams and correlation

Question 105

Markscheme

2.2.2 Scatter diagrams and correlation

Question 105

2.2.2 Scatter diagrams and correlation Questions

2.2.2 Scatter diagrams and correlation

Question 105

2.2.2 Scatter diagrams and correlation Questions