Statistics Canada provides data on the number of reportable transport accidents involving dangerous goods. In a recent year the average rate of occurrence of such accidents was 8.15 per week.

a) What probability distribution is appropriate for modelling the number of these accidents per week? State your assumptions clearly.

b) During that year, what was the probability of getting more than two such accidents in a given week?

c) Suppose that in the last week of the current year, there were two such accidents. What conclusion do you draw about last week?