Question 1
Paper 1Hard6 marksDuring fieldwork, students randomly selected 50 plots in each of three habitat types and recorded whether a particular plant species was present.
| Habitat type | Plant present | Plant absent |
|---|---|---|
| Woodland interior | 22 | 28 |
| Woodland edge | 35 | 15 |
| Open scrub | 23 | 27 |
(a)[2]
State appropriate null and alternative hypotheses for investigating whether plant presence is related to habitat type.
(b)[2]
Using an appropriate statistical test and your GDC, determine the test statistic, its degrees of freedom and the p-value.
(c)[2]
At the 5% significance level, state what the data indicate. A volunteer claims that the test proves woodland edge causes a greater probability of plant presence than open scrub. Assess this claim.