Answer:
A. 0.4249
B. 95% CI = 0.4248-0.031 < p < 0.4249+0.030
C. 80% CI = 0.4249-0.0198 < p < 0.4249+0.0198
D.95% CI is wider than 80% CI.
The more confidence you want, the wider the CI must be.
Step-by-step explanation:
Poll asked for people's opinion on whether closing local newspapers would hurt civic life; 427 of 1005 respondents said it would hurt civic life a lot.
A.The proportion of the respondents who said closing local papers would hurt civic life a lot. (round to three decimal places as needed)
427/1005 = 0.4249
B. The 95% confidence interval for the population proportion who believed closing newspaper would hurt civic life a lot. Assume the poll used a simple random sample (SRS).
Therefore, 1.96√ 0.4249×0.57/1005 = 0.0304
95% CI 0.4248-0.031 < p < 0.4249+0.030
C. 80% confidence interval for the population proportion who believed closing newspapers would hurt civic life a lot.
= 1.2820×√[0.4249×0.57/1005] = 0.0198
80% CI: 0.4249-0.0198 < p < 0.4249+0.0198
D. 95% CI is wider than 80% CI.
The more confidence you want, the wider the CI must be.
