1.) In order to estimate the mean amount of time computer users spend on the internet each month, how many computer users must be surveyed in order to be 90% confident that your sample mean is within 12 minutes of the population mean? Assume that the standard deviation of the population of monthly time spent on the internet is 219 minutes. What is a major obstacle of getting a good estimate of the population mean? Use technology to find the estimated minimum required sample size.
2.In a sample of seven cars, each car was tested for nitrogen oxide emissions(in grams per mile) and the fllowing results were obtained: 0.07, 0.08, 0.16, 0.15, 0.16, 0.14, 0.05. Assuming that this sample is representative of the cars in use, construct a 98% confidence interval estimate of the mean of the amount of nitrogen-oxide used emissions for a cars. If the EPA requires that nitrogen oxide emission be less than 0.165g/mi. Can we safely conclude that this requirement is being met?
3.A data set include 103 body temperature of healthy adult humans for which Xbar is 98.9F and s=0.67F. a.) What is the best point estimate of the mean body temperature of all healthy human? b.) Using the sample statistics, construct a 99% confidence interval estimate of the mean body temperature of all healthy humans. Does the confidence interval limit contain 98.6? What does the sample suggest about the use of 98.6Farenheit as the mean body temperature?
4.) An online site presented this question "Would the recentnorovirus outbrek deter you from taking a cruise?' Among the 34,713 people answered who responded, 65% answered "yes" Use the sample data to construct a 95% confidence interval estimate for the proportion of the population of all people who would respond "yes" to that question. Does the confidence interval provide a good estimate of the population proportion?
5.) Express the confidence interval (0.060, 0.152) in the form of p-E