An oceanographic researcher investigates the relationship between the water depth, ddd (in metres), and the dissolved oxygen concentration, ccc (in mg/L), at 22 specific sites along a vertical transect. The following summary statistics were obtained from the collected data:
Sdd=18240Scc=64.8Sdc=−846.5 S_{dd} = 18240 \quad S_{cc} = 64.8 \quad S_{dc} = -846.5 Sdd=18240Scc=64.8Sdc=−846.5Calculate the product moment correlation coefficient (rrr) for these data, giving your answer to 3 significant figures.
Interpret your value of rrr in the context of the investigation.
The researcher decides to express the depth in feet (fff) and the oxygen concentration in grams per cubic metre (ggg), using the coding f=3.28d+15f = 3.28d + 15f=3.28d+15 and g=1.0cg = 1.0cg=1.0c. State the value of the PMCC for the coded data.
202 exam-style questions on Edexcel A Level Maths Regression, Correlation and Hypothesis Testing, covering 1.1 Exponential Models, 1.2 Measuring Correlation, and 1.3 Hypothesis Testing for Zero Correlation. Each one has a worked solution and a mark scheme showing where the marks go.