Ming works as a quality assurance analyst at a bottling factory. She wants to use a one-sample z interval to estimate what proportion of 500 mL bottles are underfilled. She wants the margin of error to be no more than +4% at 90% confidence. What is the smallest sample size required to obtain the desired margin of error? 1anc wer:

Data from a representative sample were used to estimate that 33% of all computer users in a recent year had tried to get on a Wi-Fi network that was not their own in order to save money. You decide to conduct a survey to estimate this proportion for the current year. What is the required sample size if you want to estimate this proportion with a margin of error of 0.04? Calculate the required sample size first using 0.33 as a preliminary estimate of p. (Round your answer up to the nearest integer.)   The sample size of _____ should be used for this study because it will guarantee a margin of error of no greater than 0.04. The other sample size computed will only guarantee a margin of error no greater than 0.04 if  p <  _____ or if p > ______  .

we want to obtain a sample to estimate a population mean. Based on previous evidence, researchers believe the population standard deviation is approximately 38.7. We would like to be 99% confident that the estimate is within 4 of the true population mean. How large of a sample size is required ?

You want to obtain a sample to estimate a population proportion. Based on previous evidence, you believe the population proportion is approximately p = 0.85. You would like to be 97% confident that your esimate is within 4% of the true population proportion. How large of a sample size is required?