A chemical engineer is studying the relationship between the concentration of a new catalyst, ccc grams per litre, and the time taken for a specific polymerization reaction to complete, ttt minutes. The engineer suspects that there is a negative correlation between the catalyst concentration and the reaction time.
A random sample of 60 trials is conducted. The product moment correlation coefficient (PMCC) for this sample is calculated as r=−0.312r = -0.312r=−0.312.
Carry out a hypothesis test at the 1% significance level to determine if the sample provides sufficient evidence to support the engineer's suspicion.
For n=60n = 60n=60, the critical value for a one-tailed test at the 1% level for the population correlation coefficient is 0.2997.
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.