The following represents the financial information for Domingo Corporation for two months.

	March			April
Sales revenue	$	540,000		$	440,000
Costs
Process inspection	$	1,800		$	1,890
Scrap		1,840			1,860
Quality training		20,700			13,400
Warranty repairs		4,300			4,700
Product testing equipment		7,300			6,700
Customer complaints		3,000			3,500
Rework		17,000			19,000
Preventive maintenance		11,800			9,300
Materials inspection		5,900			5,200
Field testing		10,000			13,800

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.