You run the local CostCo store, and are interested in how much people spend per visit to the store, on

average, and whether they are "local" or come from some distance.The store has conducted a survey to

check on total expenditure (at the door on the way out) and to ask about the customer's postal code, which

tells whether the customer is local. The results from a sample of 100 customers are stored in the spreadsheet

CostCo.xlsx.

1. What is your estimate of the size of the average expenditure per visit (including a 95% confidence interval to indicate how accurate this is)?
2. What is your estimate of the proportion of customers who are local (again, include a 95% confidence interval to indicate how close your estimate is likely to be to the true value)?
3. The CostCo head office has said that each store should strive for an average expenditure per visit of at least $250. Does your store meet this criterion based on your sample evidence? Set up the head office statement as a hypothesis test, and draw a conclusion based on the data. Use alevel of significance for the test,a = .05.