When an opinion poll calls residential telephone numbers at random, only 20% of the calls reach a live person. you watch the random digit dialing machine make 15 calls. let x be the number calls reach a person. x has a binomial distribution. find the value of the two parameters n and p. what is the probability that exactly 3 calls reach a person? what is the probability that fewer than 3 calls reach a person? what is the probability that at least 3 calls reach a person? what is the probability at least one call reach a person?