The Minneapolis Star Tribune newspaper has decided to write an article about gasoline prices in the Twin Cities area (Minneapolis and St. Paul). The paper has designed a survey and taken a simple random sample of regular, unleaded gas prices at 35 area stations. The results are in the Area Gas Prices - Random Sample Excel file. Use this data to develop a 95% confidence interval for the average price of regular, unleaded gasoline in the area.
For regular price in Minneapolis, mean price is 3.34, standard deviation is 0.258. sample size is 35. Critical value for 95% confidence ...
This solution provides detailed explanation how to find out 95% confidence interval.