Classify the following quality costs as prevention costs, appraisal costs, internal failure costs, or external failure costs:

1. Inspection of reworked units	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
2. Inspecting and testing a newly developed product (not yet being sold)	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
3. Retesting a reworked product	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
4. Repairing a computer still under warranty	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
5. Discount allowed to customers because products failed to meet customer specifications	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
6. Goods returned because they failed to meet specifications	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
7. The cost of evaluating and certifying suppliers	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
8. Stopping work to correct process malfunction (discovered using statistical process control procedures)	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
9. Testing products in the field	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
10. Discarding products that cannot be reworked	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
11. Lost sales because of recalled products	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
12. Inspection of incoming materials	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
13. Redesigning a product to eliminate the need to use an outside component with a high defect rate	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
14. Purchase order changes	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
15. Replacing a defective product	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
16. Inspecting and testing prototypes	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
17. Repairing products in the field	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
18. Correcting a design error discovered during product development	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
19. Engineering resources used to help selected suppliers improve their product quality	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
20. Packaging inspection	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
21. Processing and responding to consumer complaints	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
22. Training production line workers in new quality procedures	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs
23. Sampling a batch of goods to determine if the batch has an acceptable defect rate	Appraisal CostsExternal Failure CostsInternal Failure CostsPrevention Costs