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=−846.5S_{dd} = 18240 \quad S_{cc} = 64.8 \quad S_{dc} = -846.5Sdd=18240Scc=64.8Sdc=−846.5
Calculate 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.
Practise Edexcel A Level Maths Regression, Correlation and Hypothesis Testing with exam-style questions for A Level Maths. 100 questions covering Exponential Models, Measuring Correlation, and Hypothesis Testing for Zero Correlation, 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.