4 A zoologist investigates the number of snakes found in a given region of land. The zoologist intends to use a Poisson distribution to model the number of snakes.
[0pt]
- One condition for a Poisson distribution to be valid is that snakes must occur at constant average rate. State another condition needed for a Poisson distribution to be valid. [1]
Assume now that the number of snakes found in 1 acre of a region can be modelled by the distribution Po(4).
[0pt] - Find the probability that, in 1 acre of the region, at least 6 snakes are found. [2]
[0pt] - Find the probability that, in 0.77 acres of the region, the number of snakes found is either 2 or 3. [4]