Question

you plan to conduct a survey to find what proportion of the workforce has two or more jobs. You decide on the 80% confidence level and state that the estimated proportion must be within 2% of the population proportion. A pilot survey reveals that 9 of the 30 sampled hold two or more jobs.

How many in the workforce should be interviewed to meet your requirements? (Round the intermediate calculations to 2 decimal places. Round the final answer to nearest whole number.)

Number of persons to be interviewed  

15)

A sample of 342 subscribers to Wired magazine shows the mean time spent using the Internet is 14 hours per week, with a sample standard deviation of 6.8 hours.

Find the 90% confidence interval for the mean time Wired subscribers spend on the Internet. (Round the final answers to 2 decimal places.)

The confidence interval is between  and

Answer 1