Question

A political candidate has asked you to conduct a poll to determine what percentage of people support him. If the candidate only wants a 4% margin of error at a 97.5% confidence level, what size of sample is needed? When finding the z-value, round it to four decimal places.

You want to obtain a sample to estimate a population proportion. At this point in time, you have no reasonable preliminary estimation for the population proportion. You would like to be 98% confident that you estimate is within 1.5% of the true population proportion. How large of a sample size is required?

A political candidate has asked you to conduct a poll to determine what percentage of people support her. If the candidate only wants a 9% margin of error at a 90% confidence level, what size of sample is needed? When finding the z-value, round it to four decimal places.

A political candidate has asked you to conduct a poll to determine what percentage of people support her. If the candidate only wants a 9% margin of error at a 90% confidence level, what size of sample is needed? When finding the z-value, round it to four decimal places.

You want to obtain a sample to estimate a population proportion. Based on previous evidence, you believe the population proportion is approximately 82%. You would like to be 98% confident that your estimate is within 2.5% of the true population proportion. How large of a sample size is required?

You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard deviation is approximately σ=34.8σ=34.8. You would like to be 99% confident that your estimate is within 1.5 of the true population mean. How large of a sample size is required?

You want to obtain a sample to estimate how much parents spend on their kids birthday parties. Based on previous study, you believe the population standard deviation is approximately σ=29.9σ=29.9 dollars. You would like to be 98% confident that your estimate is within 2.5 dollar(s) of average spending on the birthday parties. How many parents do you have to sample?

Answer 1