The Lincoln Company, Inc., produces special vacuum cleaners for conveniently cleaning the inside of cars. About a thousand of these vacuum cleaners, with stamped serial numbers, are produced every month and stored serially in a stock-room. Once a month, an inspector does a quality control check on 50 of these cleaners. When the inspector certifies them as acceptable, the units are released from the stock-room for sale. The production and sales managers, however, are not satisfied with the quality control check, since, quite often, many of the units sold are returned by customers because of various defects.
What would be the most effective sampling plan to test the 50 units? Why?
Please note that must contain at least 200 words.