A marine biologist monitors a population of Great White Sharks, collecting data on the total length, LLL meters, and the body mass, MMM tonnes, of 12 specimen sharks. The data is summarised as follows:
SLL=19.4S_{LL} = 19.4SLL=19.4 ∑M2=69.67\sum M^2 = 69.67∑M2=69.67 ∑LM=123.46\sum LM = 123.46∑LM=123.46 ∑L=50.4\sum L = 50.4∑L=50.4 ∑M=25.8\sum M = 25.8∑M=25.8
Calculate the value of SLMS_{LM}SLM and the value of SMMS_{MM}SMM.
Calculate the value of the product moment correlation coefficient (PMCC) between LLL and MMM.
Show that the equation of the regression line of MMM on LLL can be written as
M=−1.12+0.778L M = -1.12 + 0.778L M=−1.12+0.778L(Rounding constants to 3 significant figures).
Give an interpretation of the gradient of the regression line.
Explain why it would not be appropriate to use this regression line to estimate the mass of a shark with a total length of 1.2 meters.
The biologist decides to code the data using u=L−2u = L - 2u=L−2 and v=5M+3v = 5M + 3v=5M+3.
Write down the value of the PMCC between uuu and vvv.
Write down an equation of the regression line of vvv on uuu. You do not need to simplify your equation.
Practise Edexcel A Level Maths Regression, Correlation and Hypothesis Testing with exam-style questions for A Level Maths. 202 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.
