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