Question: Polling. As mentioned in the chapter, opinion-polling organizations contact their respondents by sampling random telephone numbers. Although interviewers now can reach about 76% of U.S. households, the percentage of those contacted who agree to cooperate with the survey has fallen from 58% in 1997 to only 38% in 2003 (Pew Research Center for the People and the Press). Each household, of course, is independent of the others.

a) What is the probability that the next household on the list will be contacted but will refuse to cooperate?

b) What is the probability (in 2003) of failing to contact a household or of contacting the household but not getting them to agree to the interview?

c) Show another way to calculate the probability in part b.