SOLUTION: In a survey of 320 customers, 58 say that service is poor. You select two customers without replacement to get more information on their satisfaction. What is the probability that
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-> SOLUTION: In a survey of 320 customers, 58 say that service is poor. You select two customers without replacement to get more information on their satisfaction. What is the probability that
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Question 1151656: In a survey of 320 customers, 58 say that service is poor. You select two customers without replacement to get more information on their satisfaction. What is the probability that both say service is poor?
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Let's say you have things, of which would be considered successful selections. Then the probability of making a successful selection on the first try would simply be .
But if you don't replace the thing selected on the first try, you no longer have things of which would be considered successful, you now have things of which would be successful, and the probability for the second try would be .
Since by adjusting the number of items and the number of successes you have made the two tries completely independent events, the probability of both is the product of the two individual probabilities.
So, for your problem:
