(Accounting for losses; writing) Describe how the following occurrences should be accounted for based on the fact pattern presented:
a. Certain amounts of spoilage and waste are normal in the production system and affect all jobs.
b. A certain amount of spoilage occurs that is unique to a particular job. There is no disposal value for the spoiled units.
c. Because of a nonroutine malfunction in a production machine, a number of products in Work in Process Inventory were ruined. The quantity of work lost is assumed to be abnormal. There is some salvage value for the spoiled units.