Some fast-food chains offer a lower-priced combination meal in an effort to attract budget-conscious customers. One chain test-marketed a burger, fries, and a drink combination for $1.71. The weekly sales volume for these meals was impressive. Suppose the chain wants to estimate the average amount its customers spent on a meal at their restaurant while this combination offer was in effect. An analyst gathers data from 28 randomly selected customers. The following data represent the sample meal totals.
$ 3.21, 5.40, 3.50, 4.39, 5.60, 8.65, 5.02, 4.20, 1.25, 7.64, 3.28, 5.75, 3.26, 3.80, 5.46, 9.87, 4.67, 5.86, 3.73, 4.08 5.47, 4.49, 5.19, 5.82, 7.62, 4.83, 8.42, 9.10 Use the data to construct a 90% confidence interval to estimate the population mean value. Assume the amounts spent are normally distributes.