A climatologist is investigating the relationship between the altitude, $h$ km, at which a sensor is placed and the intensity of cosmic rays, $c$ counts per minute (cpm), detected. The climatologist collects data from 8 distinct high-altitude balloons. The results are recorded in the table below.

Altitude $h$ (km)	1.1	2.4	3.5	4.2	5.8	6.5	8.1	10.3
Intensity $c$ (cpm)	210	340	420	510	800	760	1200	1550

Calculate Spearman's rank correlation coefficient for these data.

The climatologist believes that there is a positive correlation between altitude and cosmic ray intensity. Stating your hypotheses clearly, test this belief at the 5% level of significance.

State the required condition for a product moment correlation coefficient (PMCC) to be a valid test of association between these two variables.

For this sample, the mean intensity is 723.75 cpm and the median intensity is 635 cpm. Explain whether these statistics suggest that the condition stated in part (c) is likely to be met.

Altitude $h$ (km)	1.1	2.4	3.5	4.2	5.8	6.5	8.1	10.3
Intensity $c$ (cpm)	210	340	420	510	800	760	1200	1550

Calculate Spearman's rank correlation coefficient for these data.

The climatologist believes that there is a positive correlation between altitude and cosmic ray intensity. Stating your hypotheses clearly, test this belief at the 5% level of significance.

State the required condition for a product moment correlation coefficient (PMCC) to be a valid test of association between these two variables.

For this sample, the mean intensity is 723.75 cpm and the median intensity is 635 cpm. Explain whether these statistics suggest that the condition stated in part (c) is likely to be met.

2.2.2 Scatter diagrams and correlation

Question 85

Markscheme

2.2.2 Scatter diagrams and correlation

Question 85

Markscheme

2.2.2 Scatter diagrams and correlation

Question 85

2.2.2 Scatter diagrams and correlation Questions

2.2.2 Scatter diagrams and correlation

Question 85

2.2.2 Scatter diagrams and correlation Questions