The following represents the financial information for Domingo Corporation for two months. April $390,000 Sales revenue Costs Process inspection Scrap Quality training Warranty repairs Product testing equipment Customer complaints Rework Preventive maintenance Materials inspection Field testing March $500,000 $1,650 1,840 19,700 4,400 6,600 2,500 17,000 13,500 6,300 8,900 $ 1,950 1,970 12,800 4,900 7,100 3,200 16,500 9,500 4,700 13,900 Required: a. Classify these items into Prevention, Appraisal, Internal failure, or External failure costs. b. Calculate the ratio of the prevention, appraisal, internal failure, and external failure costs to sales for March and April.