Mathematics 9709 · AS & A Level · The Poisson distribution
The Poisson distribution — practice question
People visiting a Wildlife Park in Africa have independent chances of $0.9$ of seeing giraffes, $0.95$ of seeing elephants, $0.85$ of seeing zebras and $0.1$ of seeing lions.
(i)[1]
Find the probability that a visitor to the Wildlife Park sees every one of these animals.
(ii)[3]
Find the probability that, among 12 visitors chosen at random, fewer than 3 see lions.
(iii)[2]
50 people independently visit the Wildlife Park. Find the mean and variance of how many of these people see zebras.
Worked solution & mark scheme
This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Accurate probability calculation $0.9\times0.95\times0.85\times0.1$” …