A sales firm receives, on average, 3 calls per hour on its toll-free number. LetXrepresent the number of calls received in a given hour. AssumingXhas a Poisson distribution.

a) For any given hour, find the probability that it will receive the following.

1. At most 3 calls
2. At least 3 calls
3. 5 or more calls
4. b) Calculate
5. = E(X) =
6. (X) =