A medical researcher records the age and systolic blood pressure of 20 patients. The product moment correlation coefficient for this data is calculated as r=0.482r = 0.482r=0.482.
Stating your hypotheses clearly test, at the 1% significance level, whether there is a positive correlation between age and systolic blood pressure.
47 exam-style questions on OCR (MEI) A Level Maths 2.5.11 Inference using a correlation coefficient (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.