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# Sample size and confidence interval

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A1)
Suppose the U.S. President wants an estimate of the proportion of the population who support his current policy toward revisions in the Social Security system. The president wants the estimate to be within .04 of the true proportion. Assume a 95 percent level of confidence. The president's political advisers estimated the proportion supporting the current policy to be .60.

How large of a sample is required?
How large of a sample would be necessary if no estimate were available for the proportion supporting current policy?

A2)
A state meat inspector in Iowa has been given the assignment of estimating the mean net weight of packages of ground chuck labeled '3 pounds'. Of course, he realizes that the weights cannot be precisely 3 pounds. A sample of 36 packages reveals the mean weight to be 3.01 pounds, with a standard deviation of 0.03 pounds.

What is the estimated population mean?
Determine a 95 percent confidence interval for the population mean.