Degree of Confidence

13. Use the given degree of confidence and sample data to construct a confidence interval for the population proportion p.
A survey of 865 voters in one state reveals that 408 favor approval of an issue before the legislature. Construct the 95% confidence interval for the true proportion of all voters in the state who favor approval. (Points : 5)
0.471 < p < 0.472
0.435 < p < 0.508
0.438 < p < 0.505
0.444 < p < 0.500
 

14. Solve the problem.
A newspaper article about the results of a poll states: “In theory, the results of such a poll, in 99 cases out of 100 should differ by no more than 5 percentage points in either direction from what would have been obtained by interviewing all voters in the United States.” Find the sample size suggested by this statement. (Points : 5)
544
664
27
385
 

16. Use the confidence level and sample data to find a confidence interval for estimating the population mu. Round your answer to the same number of decimal places as the sample mean.
Test scores: n = 92, mean = 90.6, sigma = 8.9; 99% confidence (Points : 5)
88.4 < mu < 92.8
88.8 < mu < 92.4
88.2 < mu < 93.0
89.1 < mu < 92.1