Final answer:
The correct option is c. Utilize the AQL and reject lots based on inspection results.
To design a sampling plan with a 2% Acceptance Quality Level and a 5% rejection rate, use of inspection results based on the AQL (option c) is appropriate. This plan uses statistical tools to determine sample size and acceptance criteria, balancing risks of accepting or rejecting lots.
Step-by-step explanation:
In response to the question of designing a sampling plan that ensures lots of quality 2% will be rejected 5% of the time, we would look at option (c). This involves utilizing the specified Acceptance Quality Level (AQL) and basing rejection of lots on inspection results. An effective sampling plan would involve establishing a sample size and acceptance/rejection criteria based on the AQL. This helps in maintaining a balance between the risk of accepting a bad lot and the risk of rejecting a good one.
Option (a) using random sampling without any specific plan is not adequate as it does not consider the AQL and the desired rejection rate. Option (b) is subjective and may not align with quality standards. Option (d) is too strict and does not provide a practical approach to assessing the lot quality. In a proper sampling plan, statistical tools such as Operating Characteristic (OC) curves are used to determine the probability of acceptance against various levels of lot defectiveness, ensuring that lots with a defect rate at or below the AQL have a high probability of being accepted, while lots exceeding the AQL are more likely to be rejected.