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 of error of 1.7 milligrams per liter (mg/L), how many water specimens are required in the sample? Assume prior knowledge indicates that pollution readings in water samples taken during a day are approximately normally distributed with a standard deviation equal to 7 mg/L.
The company must sample______water specimens in order to estimate the mean daily rate of pollution produced by a mining operation to 1.7 mg/L with 95 % confidence.
(Round up to the nearest specimen.)
Given that, standard deviation = 7 mg/L
margin of error ( E ) = 1.7 mg/L
A 95% confidence level has significance level = 0.05 and critical value is,
We want to find, the sample size ( n ),
Therefore, The company must sample 65 water specimens in order to estimate the mean daily rate of pollution produced by a mining operation to 1.7 mg/L with 95 % confidence.
A company wants to test a randomly selected sample of n water specimens and estimate the...
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