A biochemist is investigating the relationship between the concentration of a catalyst, CCC (in mg/L), and the rate of a specific chemical reaction, RRR (in units/sec). The results for 8 unique samples are recorded in the table below.
| Sample | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
|---|---|---|---|---|---|---|---|---|
| CCC | 1.2 | 0.5 | 3.8 | 2.1 | 0.9 | 4.5 | 1.7 | 2.9 |
| RRR | 14.2 | 6.4 | 28.5 | 19.1 | 11.8 | 35.2 | 10.5 | 22.7 |
Calculate the Spearman's rank correlation coefficient between CCC and RRR.
A laboratory colleague claims that there is no correlation between the catalyst concentration and the reaction rate in the population from which these samples were drawn.
Test, at the 5% level of significance, the colleague's claim. State your hypotheses clearly. (Critical value for n=8n=8n=8 at 5% two-tailed is 0.7381)
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.