The waterworks commission needs to know the mean household usage of water by the residents of a small town in gallons per day. They would like to estimate to have a maximum error of 0.13 gallons. A previous study found that for an average family the variance is 2.56 gallons and the mean is 16.3 gallons per day. If they are using 80% level of confidence, how large of a same is required to estimate the mean usage of water? round answer  up to the next integer.

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A: Solution

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Q: The electric cooperative needs to know the mean household usage of electricity by its non-commercial…

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