A quality control manager wants to determine the percentage of defective light bulbs in the production line. Which of the following sampling methods would most likely lead to a valid inference? A testing the last 4,000 bulbs in the production line, B testing every 50th light bulb in the production line, C retesting 100 light bulbs that have already been tested, or detesting the first 2000 light bulbs in the production line? Which one is correct?
B testing every 50th light bulb in the production line.
This sampling method ensures a random and representative sample of the production line, which would most likely lead to a valid inference about the percentage of defective light bulbs in the entire production line. It provides a systematic way to select samples without bias. Testing the last 4,000 bulbs, retesting already tested light bulbs, or testing the first 2000 light bulbs could introduce bias into the sample and lead to inaccurate results.