Question 59559
A New York Times article about Poll results states, "In theory, in 19 cases out of 20, the results from such a poll should differ by no more than one percentage point in either direction from what would have been obtained by interviewing all voters in the United States. Find the sample size suggested by this statement.
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The formula for sample size is n=[z^*sigma/E]^2
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You want n.
You have the following information:
"19 out of 20" indicates you want a 95% confidence result which means 
z^*=2.5758...
"differ no more than one percentage point" means E=0.01
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Missing information:
You are missing the value of sigma.
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If you have sigma you can calculate n.
Cheers,
Stan H.