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.
316 exam-style questions on OCR A Level Maths 2.5 Statistical Hypothesis Testing, covering 2.5.1 The language of hypothesis testing, 2.5.2 Hypothesis test for a binomial proportion, 2.5.3 Inference and significance level, 2.5.4 Sample mean as a random variable (A-level only), 2.5.5 Hypothesis test for the mean of a normal distribution (A-level only), 2.5.6 Pearson's product-moment correlation coefficient, and 2.5.7 Hypothesis test using Pearson's coefficient (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.