A botanist is investigating the relationship between the moisture content of soil, MMM (measured as a percentage), and the final growth height of a specific seedling species, HHH (measured in cm). The data for 8 test plots are recorded in the table below.
| Plot | A | B | C | D | E | F | G | H |
|---|---|---|---|---|---|---|---|---|
| Moisture (MMM %) | 25 | 12 | 38 | 55 | 30 | 42 | 18 | 50 |
| Height (HHH cm) | 18.3 | 10.1 | 25.4 | 32.8 | 15.2 | 28.1 | 14.9 | 20.5 |
Calculate Spearman's rank correlation coefficient for these data.
Stating your hypotheses clearly, test at the 5% level of significance whether there is evidence of a positive correlation between soil moisture content and seedling growth height.
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.