如何求DPMO

Broadwork Electronics manufactures 500,000 circuit boards per month. A random sample of 5,000 boards is inspected every week for five characteristics. During a recent week, two defects were found for one characteristic, and one defect each was found for the other four characteristics. If these inspections produced defect counts that were representative of the population, what are the dpmo’s for the individual characteristics and what is the overall dpmo for the boards?