Practise deciding when Poisson is a suitable model for random events and calculating context-based probabilities with CAIE Mathematics AS questions.
Sales of cell phones at a certain shop occur singly, randomly and independently.
State one further condition that must be satisfied for the number of sales in a certain time period to be well modelled by a Poisson distribution.
The average number of sales per hour is 1.2 .
Assume now that a Poisson distribution is a suitable model.
Constant average rate
OE
Marking guidance:
Accept constant rate. Allow without context.