Sample size to be 99% confident that results are accurate

A researcher would like to estimate the average age of physicians at a clinic. How large does the sample need to be if the researcher would like to be 99% confident that the estimate is accurate within one year. From a previous study, the standard deviationof age is known to be 3 years. Provide an interpretation of the results.

The z- score for 99% confidence is z = 2.576

Sample size, N = (z * sigma / …

This solution contains step-by-step calculations to determine the sample size in order to be 99% confident that the result is accurate.