probability and statistics

Question

An opinion poll calls 1334 randomly chosen residential telephone numbers, then the interviewer asks to speak with an adult member of the household to ask "How many movies have you watched in a movie theater in the past 12 months?" In all, 931 people respond. What is the rate (to the nearest tenth of a percent) of nonresponse?

Answer 1

non-response rate (in %) = 100 * (1334 - 931)/1334