Question: Safe cities. An October 2006 Gallup Poll asked a random sample of 1001 adults to rate each of 16 large cities as safe to live in or visit, or not. Among the respondents, 800 rated Seattle as safe. We can act as if the sample were an SRS. Give 90% and 99% confidence intervals for the proportion of all adults who think Seattle is safe. Explain briefly what important fact about confidence intervals is illustrated by comparing these two intervals and the 95% confidence interval from Exercise.
Exercise: Safe cities. An October 2006 Gallup Poll asked a random sample of 1001 adults to rate each of 16 large cities as safe to live in or visit, or not. Among the respondents, 800 rated Seattle as safe. We can act as if the sample were an SRS. Give a 95% confidence interval for the proportion of all adults who would rate Seattle as safe to live in or visit.