This document discusses how to calculate a confidence interval for a mean. It outlines that the sampling distribution must be approximately normally distributed and use simple random sampling. It describes the steps as calculating the sample statistic, choosing a confidence level, determining the margin of error using the standard deviation or standard error, and specifying the confidence interval as the sample statistic plus or minus the margin of error. It also notes that when the population is at least 10 times the sample size, the standard error can be approximated from tables, and when the population standard deviation is unknown, a t-score must be used instead.