A glaciologist suggests that there is a negative correlation between the concentration of a specific microplastic, ppp parts per billion, in snow samples and the distance, ddd km, from the nearest research station.
The glaciologist analyzed a random sample of 25 locations and calculated the product moment correlation coefficient (PMCC) between the microplastic concentration and distance to be −0.415-0.415−0.415.
Carry out a hypothesis test at the 5% significance level to determine if this sample provides sufficient evidence to support the glaciologist's suggestion.
For n=25n = 25n=25, the critical value for a one-tailed test at the 5% level for the population correlation coefficient is 0.33650.33650.3365.
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.