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Question 347866:
Found 3 solutions by stanbon, Fombitz, poliet:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
A bin contains 77 light bulbs of which 12 are defective. If 5 light bulbs are randomly selected from the bin with replacement, find the probability that all the bulbs selected are good ones. My original answer was .844 and it was wrong.
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Ans: (65/77)^5 = 0.4287
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Cheers,
Stan H.

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
So the bin has 65 good, 12 bad, 77 total.
P(1st good)=65%2F77
P(2nd good)=65%2F77
P(3rd good)=65%2F77
P(4th good)=65%2F77
P(5th good)=65%2F77
P(all good)=%2865%2F77%29%2865%2F77%29%2865%2F77%29%2865%2F77%29%2865%2F77%29
P(all good)=0.4287
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P=0.844 is the probability of picking the first good one out.
But you're doing it 5 times, so you need to multiply that value 5 times.

Answer by poliet(1) About Me  (Show Source):