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 6% margin of error at a 90% confidenc

Algebra ->  Probability-and-statistics -> 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 6% margin of error at a 90% confidenc      Log On


   



Question 1120154: #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 6% margin of error at a 90% confidence level, what size of sample is needed?
Give your answer in whole people.

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
error = +/- z*sqrt p*(1-p)/n
0.06=1.645*sqrt (0.25)/n
0.06=1.645*0.5/sqrt (n)
0.06 sqrt (n)=0.8225
divide by 0.06 both sides and square
n=187.92 or 188