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When constructing a confidence interval for a population mean with σ known, the margin of error is E = zα/2 √σ n . If you want a confidence interval at the 80% confidence level, what is the value for zα/2?

User Andrew Meyer
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1 Answer

29 votes
29 votes

Step-by-step explanation

The margin of error is given by the formula


E=Z_{(\propto)/(2)}\frac{\sigma}{\sqrt[]{n}}

To get the value of


\begin{gathered} Z_{(\propto)/(2)} \\ \text{from tables} \\ \end{gathered}

The value is 1.28

When constructing a confidence interval for a population mean with σ known, the margin-example-1
User Dgrijuela
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