An agricultural scientist observed that the product moment correlation coefficient between the amount of rainfall (in mm) and the yield of a specific crop (in tonnes per hectare) for a sample of 30 farms was 0.412. The data is assumed to come from a bivariate normal distribution. Carry out a hypothesis test at the 5% significance level to determine whether there is a positive correlation between rainfall and crop yield. The critical value for the correlation coefficient at the 5% significance level for a sample size of 30 is 0.3061.
202 exam-style questions on Edexcel A Level Maths Regression, Correlation and Hypothesis Testing, covering 1.1 Exponential Models, 1.2 Measuring Correlation, and 1.3 Hypothesis Testing for Zero Correlation. Each one has a worked solution and a mark scheme showing where the marks go.