The monthly rainfall, xxx mm, and the average wind speed, yyy knots, were recorded in 10 coastal locations over a period of one month. The data are summarised below:
Sxx=4 225S_{xx} = 4\,225Sxx=4225 ∑y=145\sum y = 145∑y=145 ∑y2=2 250\sum y^2 = 2\,250∑y2=2250 Sxy=652.5S_{xy} = 652.5Sxy=652.5
Find SyyS_{yy}Syy.
Calculate, to 3 significant figures, the product moment correlation coefficient for these data.
Give an interpretation of your coefficient in context.
A researcher decides to use the variable www to represent rainfall in centimetres, where w=x10w = \frac{x}{10}w=10x.
Write down the value of SwwS_{ww}Sww.
Write down the value of the product moment correlation coefficient between www and yyy.
Practise Edexcel A Level Maths Measuring Correlation with exam-style questions for A Level Maths. 108 questions, 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.
