SOLUTION: #8
A political candidate has asked you to conduct a poll to determine what percentage of people support her.
If the candidate only wants a 2% margin of error at a 95% confidenc
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A political candidate has asked you to conduct a poll to determine what percentage of people support her.
If the candidate only wants a 2% margin of error at a 95% confidenc
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Question 1120078: #8
A political candidate has asked you to conduct a poll to determine what percentage of people support her.
If the candidate only wants a 2% margin of error at a 95% confidence level, what size of sample is needed?
Give your answer in whole people. Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! As a proportion use 0.5 as the most conservative estimate.
The error is +/-z * std error
z=1.96 for 95% CI
SE is sqrt p*(1-p)/n
This is sqrt 0.25/n
Therefore 1.95*0.5/sqrt(n)=0.02
0.975=0.02 sqrt (n)
divide both sides by 0.02 and then square them.
n=2376.56 or 2374 people.
