The article “An Association Between Fine Particles and Asthma Emergency Department Visits for Children in Seattle” [Environmental Health Perspectives June, 1999 107(6)] used Poisson models for the number of asthma emergency department (ED) visits per day. For the zip codes studied, the mean ED visits were 1.8 per day. Determine the following:

(a) Probability of more than five visits in a day.

(b) Probability of fewer than five visits in a week.

(c) Number of days such that the probability of at least one visit is 0.99.

(d) Instead of a mean of 1.8 per day, determine the mean visits per day such that the probability of more than five visits in a day is 0.1.