A sample survey to estimate the fast-food market in a large city was kept small enough to allow repeated follow-up. The high response rate meant that the sample was essentially random. The survey recorded the number of fast-food meals eaten by each person in the previous 7 days, and the average is 0.82 with standard deviation of 0.48. Sample size of 180. Calculate a 95% confidence interval for the mean of the whole population of this city. You may assume a two-tailed test.