Assume that a sample is used to estimate a population proportion p. Find the margin of error M.E. that corresponds to a sample of size 342 with 37.1% successes at a confidence level of 99.5%.

Determine the sample size needed to estimate a population with a mean of 10 units given that the population standard deviation is 50; use a confidence level of 90%.

Assume that a sample is used to estimate a population mean. Find the 90% confidence interval for a smaple of size 46 with a mean of 68.5 and a standard deviation of 6.6. Enter the answer as an open-interval (parentheses) accurate to one decimal place (because the sample statistics are reported accurate to one decimal place).

A researcher wants to make a 95% confidence interval for the population mean. She wants the maximum error of estimate to be within 4.8 of the population mean. The population standard deviation is 18.65. What would be the sample size the yield a maximum error of estimate within 4.8 of the population mean?

Work Time Lost due to Accidents At a large company, the Director of Research found that the average work time lost by employees due to accidents was 102 hours per year. She used a random sample of 21 employees. The standard deviation of the sample was 5.4 hours. Estimate the population mean for the number of hours lost due to accidents for the company, using a 99% confidence interval. Assume the variable is normally distributed. Use a graphing calculator and round the answers to the nearest whole number.

In a random sample of twelve people, the mean driving distance to work was 21.3 miles and the standard deviation was 7.3 miles. Assume the population is normally distributed and use the t-distribution to find the margin of error and construct a 99% confidence interval for the population mean μ. Interpret the results. Identify the margin of error. (Rol square miles miles per hour miles s needed.)

Determine the margin of error in estimating the population mean, μ. Based on a sample of size 44, a 95% confidence interval for the mean score of all students, μ, on an aptitude test is from 67 to 72. Find the margin of error.

The operations manager of a large production plant would like to estimate the average amount of time workers take to assemble a new electronic component. After observing a number of workers assembling similar devices, she guesses that the standard deviation is 6 minutes. How large a sample of workers should she take if she wishes to estimate the mean assembly time to within 18 seconds. Assume the confidence level to be 91%. Sample Size =

If the sample mean is 8, the hypothesized population mean is 4, and the population standard deviation is 2, compute the test value needed for the z test.