An agricultural inspector finds that 18% of cocoa trees in a large plantation have been affected by a particular fungal spore.
State a distribution that is suitable to model the number of affected trees in a random sample of 50 trees.
State two conditions for the distribution in part (a) to be a valid model.
Find the probability that:
exactly 10 trees in a sample of 50 are affected,
Find the probability that:
fewer than 4 trees in a random sample of 25 trees are affected.
A regional agriculture officer notes that resources will be strained if more than 160 trees are found to be affected in a specific plantation block containing 800 trees.
Using a suitable approximation, find the probability that resources will be strained in a particular plantation block.
324 exam-style questions on WJEC A Level Maths 4.2 Statistical distributions (A-level only), covering 4.2.1 Statistical distributions (A-level only), 4.2.2 Statistical distributions (A-level only), and 4.2.3 Statistical distributions (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.