Question 802203
an economist wants to estimate the mean income for the first year of work for college graduates who have had the profound wisdom to take a statistics course. How many such incomes must be found if we want to be 95% confident interval that the sample mean is within $500 of the true population mean?
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n = [z*s/E]^2
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n = [1.96*s/500]^2
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You need the standard deviation to find a value for "n".
Cheers,
Stan H.
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