- #1
teme92
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Homework Statement
A manager must assess the quality of a new batch of 25 components ready for shipping.
Rather than assess each component, a sample of 5 is randomly selected and tested. The
quality control speci fication is that if there are 2 or more defectives in the sample, the
quality manager must reject the batch. Suppose there are actually 3 defective components
in this batch of 25.
What is the probability that the batch is rejected?
Homework Equations
The Attempt at a Solution
So I'm looking for the probability that 2 or 3 defective parts are taken in the sample of 5. I'm having trouble wrapping my head around the problem a bit.
I said the probability of choosing all 3 is:
(3/25).(2/24).(1/23)=1/2300
What's confusing me is that this has only three picks when there's five parts picked in the sample. Am I missing something here? Any help would be much appreciated.