ave a mean life of 800 hours with a standard deviation of 40 hours. A customer may find that 50 bulbs had a mean life of 790 hours and claims that the manufacturer is misstating the reliability of the bulbs. Using a normal distribution and calculating the standard deviation, the probability that the manufacturer's claims are accurate (or not) can be established.
Combining the normal distribution with principles of probability is one of the most common uses of the normal distribution. This practice has gained particular popularity with political pollsters who use the normal distribution and principles of sampling to determine how voters will vote and who will win an election based on early returns.
The reason that statisticians are able to apply probability theory to normal di
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