A random sample of 40 oak trees was studied by a biologist. She recorded the height hhh in meters and the trunk diameter ddd in centimeters of each tree.
The following summary statistics were calculated from these data:
∑h=680,∑h2=11776,∑d=1440,∑hd=25012,Sdd=2240\sum h = 680, \quad \sum h^2 = 11776, \quad \sum d = 1440, \quad \sum hd = 25012, \quad S_{dd} = 2240∑h=680,∑h2=11776,∑d=1440,∑hd=25012,Sdd=2240
Find ShhS_{hh}Shh and ShdS_{hd}Shd.
Calculate, to 3 significant figures, the product moment correlation coefficient between hhh and ddd.
Give an interpretation of your coefficient in the context of the biologist's study.
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.