A travel agency is concerned with the accuracy as well as appearance of itineraries prepared for its clients. Defects can comprise errors in times, airlines, flight numbers, prices, car rental information, lodging, charge card numbers and reservation numbers as well as typographical errors. As the possible number of mistakes is nearly infinite the agency measures the number of errors that do occur. The current process results in an average of three errors per itinerary.
(a) Explain what are the two-sigma control limits for three defects?
(b) Dr Liu scheduled a tour to Dallas for her conference last week. Her itinerary contained six errors. Understand this information based on your real experience as well as the result from part (a)