Question 618748
In an effort to check the quality of their cell phones, a manufacturing manager decides to take a random sample of 10 cell phones from yesterday’s production run of 2000 phones. If each of the 2000 phones is likely to be selected:
i)What is the probability that a randomly selected cell phone will be one of the last 80 produced?
Ans: 80/2000 = 8/200 = 1/25
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ii)What is the probability that the first cell phone selected is either from the last 160 produced or from the first 90 to be produced?
Ans: (160 + 90)/2000 = 250/2000 = 1/8
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iii)What is the probability that the first two cell phones are both from the last 80 produced?
P(1st 2 from last 80) = (1/25)(1/25) = 1/625
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Cheers,
Stan H.
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