4. (10 points) In the study of a certain aquatic organism, a large number of samples were taken from a pond, and the number of organisms in each sample was counted. The average number of organisms per sample was found to be two. Assuming that the number of organisms follows a Poisson distribution, answer the following: (a) What is the probability that in the next 3 samples taken will contain one or fewer organisms? (b) What is the probability that in the next 3 samples taken will contain exactly three organisms? (c) What is the probability that in the next 3 samples taken will contain more than five organisms