SOLUTION: A politician running for a local office wants to get a snap shot of how he is doing at the poll. What sample size is needed to construct a 98% confidence interval for the proportio
Algebra ->
Finance
-> SOLUTION: A politician running for a local office wants to get a snap shot of how he is doing at the poll. What sample size is needed to construct a 98% confidence interval for the proportio
Log On
Question 1088241: A politician running for a local office wants to get a snap shot of how he is doing at the poll. What sample size is needed to construct a 98% confidence interval for the proportion that will vote for him with no more than a 1% margin of error? Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! Largest CI or most conservative is when p=0.5, for p*(1-p) is a maximum when both are 0.5
the interval is +/-2.33*sqrt(.5*.5/n)=0.01
square both sides
5.4289*0.5/n=0.0001
n=5.4289*0.5/0.0001
n-27,145, rounded up.
