A purchaser receives small lots (N = 25) of a high precision device. She wishes to reject the lot 95% of
the time if it contains as many as seven defectives. Suppose she decides that the presence of one defective in
the sample is sufficient to cause rejection. How large should her sample size be?
Its not given how many defectives are there in the entire lot of 25 items. How do I proceed then?
No. of defectives cant be 6 otherwise the lot will never be rejected.
But it could be anything more than 6. It could be 7 also. Could be 8. How do I decide that.
The purchaser wants a 95% accuracy in her sample. But that deosnt give me any idea on the no. of defectives contained in the lot
Does it make sense to assume that all 25 are defective?
But will that setup work if there are only 20 defectives? 10 defectives? 7 defectives? The point is that you need to plan for the hardest possible case to detect.
i think i got it...
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