The number of stork sightings on a route in South Carolina follows Poisson process with a mean of 2.3 per year.
(a) What is the mean time between sightings within three months (25 years)?
(b) What is the probability that there are no sightings within three months?
(c) What is the probability that the time until the first sighting exceeds six months?
(d) What is the probability of no sightings within three years?