# Probability and Sample Mean

The lifetime of a certain brand of batteries are known to be normally distributed with a mean of 1600 hours and a standard deviation of 400 hours. A random sample of 64 of these batteries is taken. What is the probability that the sample mean lifetime is more than 1500 hours?

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The lifetime of a certain brand of batteries are known to be normally distributed with a mean of 1600 hours and a standard deviation of 400 hours. A random sample of 64 of these batteries ...

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The solution uses a random sample of 64 batteries to find the probably and sample mean of the lifetime of the batteries.

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