Fairfield, J. H. (1959, ASQC) Argus Camera Company
When the characteristics of two lots fit specified assumptions, a comparison for a significant difference can be made very quickly with a nomograph presented by the author. For example, consider two lots of 5000 condensers offered to a radio manufacturer. A sample of 100 from lot 1 and 200 from lot 2 are tested for breakdown voltage, revealing 10 and 30 defectives respectively. Which lot should be purchased?