Posted by **Joy** on Wednesday, August 10, 2011 at 12:18am.

The probability that a person has an unlisted telephone number is 0.15. The district manager of

a political action group is phoning people urging them to vote. In a district with 416 households, all households have phones. What is the probability that the district manger will find that:

(a) 50 or fewer households in the district will have unlisted numbers?

(a) 345 or more have listed phone numbers?

(c) between 40 and 80 have unlisted numbers?