State two conditions under which it might be more appropriate to use Spearman’s rank correlation coefficient rather than the product moment correlation coefficient.
A researcher took a random sample of 12 luxury watches from a boutique. The price, in pounds, and the age, in years, of each watch were recorded.
The Spearman’s rank correlation coefficient between the results was calculated as rs=−0.598r_s = -0.598rs=−0.598.
Test, at the 5% level of significance, whether or not there is evidence of a correlation. State clearly your hypotheses and the critical value used.
The product moment correlation coefficient (PMCC) between the results was calculated as r=−0.482r = -0.482r=−0.482.
Test, at the 5% level of significance, whether or not there is evidence of a negative correlation. State clearly your hypotheses and the critical value used.
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.
