An Advertising Executive Receives an Average of 10 Telephone Calls

Essay

An advertising executive receives an average of 10 telephone calls each afternoon between 2 and 4pm. The calls occur randomly and independently of one another.
a. Find the probability that the executive will receive 13 calls between 2 and 4pm on a particular afternoon.
b. Find the probability that the executive will receive seven calls between 2 and 3pm on a particular afternoon.
c. Find the probability that the executive will receive at least five calls between 2 and 4pm on a particular afternoon.