Final answer:
False. The assertion that acceptance sampling guarantees a lot free of defects is false. Acceptance sampling is about meeting a threshold of quality based on statistical sampling, not certifying a lot as defect-free.
Step-by-step explanation:
The statement that a lot that is accepted by acceptance sampling is certified to be free of defects is false. Acceptance sampling is a statistical quality control method where a random sample is taken from a lot, and based on the results, the lot is either accepted or rejected. However, the acceptance of a lot does not mean it is completely free of defects; it simply means that the quality of the batch meets the predetermined threshold for the number of acceptable defects. The underlying principle is based on the probability that the sample reflects the true state of the entire lot within certain confidence levels.
It must be noted that when sample size is greater than 30, as mentioned in the reference to normal distribution being an excellent approximation, it implies that the larger the sample, the more it tends to reflect the actual conditions of the batch. However, this still does not guarantee defect-free products, but rather a statistically acceptable level of quality.