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As part of a water quality​ survey, you test the water hardness in several randomly selected...

As part of a water quality​ survey, you test the water hardness in several randomly selected streams. The results are shown below. Construct a confidence interval for the population variance sigma squaredσ2 and the population standard deviation sigmaσ.Use a 95 % level of confidence. Assume that the population has a normal distribution.

nequals=23

sequals=16 grains per gallon

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