A random sample of 507 adults is used to investigate correlation between forearm girth and bicep girth. Software gives R2=0.8881R^2=0.8881R2=0.8881, and the fitted line has positive gradient.
Find the sample product moment correlation coefficient.
Explain why printed statistical tables ending at sample size 100 cannot be used directly.
State an appropriate way to complete the test.
Explain why a statistically significant result need not imply a useful causal relationship.
178 exam-style questions on WJEC A Level Maths 4.3.1 Statistical hypothesis testing (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.