Confidence Interval for the Population Mean

A small town has a population of 20,000 people. Among these 1,000 regularly visit a popular local bar. A sample of 100 people who visit the bar is surveyed for their annual expenditures in the bar. It is found that on average each person who regularly visits the bar spends about $1500 per year in the bar with a standard deviation of $120. Construct a 99 percent confidence interval around the mean annual expenditure in the bar.