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## A company wants to test a randomly selected sample of n water specimens and estimate the mean daily rate of pollution produced by a mining operation.

A company wants to test a randomly selected sample of n water specimens and estimate the mean daily rate of pollution produced by a mining operation. If the company wants a 95% confidence interval estimate with a margin or error of 1.5 milligrams per liter (mg/L), how many water specimens are required in the sample? Assume prior knowledge indicates that pollution in water samples taken during a day are approximately normally distributed with a standard deviation equal to 8 mg/L.

The company must sample ___ water speciments in order to estimate the mean daily rate of polluation produced by a mining operation to 1.5 mg/L with 95% confidence.