Exam 8: Estimation and Confidence Intervals

College X is concerned about their employees making use of their email for non-business purposes. You have been approached to assist in this matter. College X decides on a 95% confidence level and state that the estimation proportion must be within 2 percent of the population proportion. A pilot survey reveals that 8 out of 50 emails sampled were not for business purposes. How many emails should be surveyed to meet your requirements?

A sample mean is the best point estimate of the

A confidence interval for a population mean

The distribution of Student's t has

The Sugar Producers Association wants to estimate the mean yearly sugar consumption. A sample of 25 people reveals the mean yearly consumption to be 27 kg with a sample standard deviation of 9 kg. Assume a normal population. Develop a 90% confidence interval for the mean annual consumption of sugar.

The z-value associated with a 90% level of confidence is:

College X is concerned about their employees making use of their email for non-business purposes. A random sample of 400 e-mails discovered 60 messages that were not business related. The 99% Confidence interval for the population proportion is:

A survey of an urban university (population of 25,450) showed that 870 of 1,100 students sampled supported a fee increase to fund improvements to the student recreation center. Using the 99% level of confidence, what is the confidence interval?