Question: Been to the movies? An opinion poll calls 2000 ran domly chosen residential telephone numbers, then asks to speak with an adult member of the household. The interviewer asks, "How many movies have you watched in a movie theater in the past 12 months?" In all, 1131 people responded. The researchers used the responses to estimate the mean number of movies adults have watched in a movie theater in the past 12 months.
(a) Describe a potential source of bias related to the wording of the question. Suggest a change that would help fix this problem.
(b) Describe how using only residential phone numbers might lead to bias and how this will affect the estimate.
(c) Describe how nonresponse might lead to bias and how this will affect the estimate.