Question 1

Paper 1Easy6 marks

A student records the distance downstream from a spring and the number of aquatic invertebrate taxa found at each of six fieldwork sites. Figure 1 shows the results.

012345678910024681012Distance downstream from the spring, d (km)Number of aquatic invertebrate taxa, N
(a)

Using your GDC, find Spearman’s rank correlation coefficient, rsr_s for these data. Give your answer to three significant figures.

[2]
(b)

Using your GDC, find Pearson’s product moment correlation coefficient, rr for these data. Give your answer to three significant figures.

[2]
(c)

The student wants to describe a monotonic association, and considers the point (10,5)(10,5) to be unusual compared with the other observations. State which coefficient is more appropriate for this purpose and give a reason.

[2]

More AI 4.2 Correlation and regression questions