Random digit dialing
Most sample surveys use random digit dialing equipment to call residential telephone numbers at random. The telephone polling ?rm Zogby International reports that the probability that a call reaches a live person is 0.2.9 Calls are independent.
(a) A polling ?rm places 5 calls. What is the probability that none of them reaches a person?
(b) When calls are made to New York City, the probability of reaching a person is only 0.08. What is the probability that none of 5 calls made to New York City reaches a person?