SOLUTION: You wish to estimate with 90% confidence, the proportion of U.S. adults who made one or more emergency room visits in the past year. How large of a sample will you need if your es

Question 1141129: You wish to estimate with 90% confidence, the proportion of U.S. adults who made one or more emergency room visits in the past year. How large of a sample will you need if your estimate is to be within 3% of the population proportion?
Answer by Boreal(15235) (Show Source): You can put this solution on YOUR website!
Largest number or most conservative estimate assumes proportion is 0.5
the half-interval is z*sqrt(p*(1-p)/n)=0.03, the error.
square both sides and multiply through by n
1.645^2*0.25=0.0009n
n=751.67 or 752 people
RELATED QUESTIONS
A hospital emergency room has collected a sample of n = 40 to estimate the mean number of (answered by jim_thompson5910,stanbon)

You wish to estimate with a 95% confidence the population proportion of kids who say red... (answered by jim_thompson5910)

I'm having some difficulty with this problem: FOX News conducted an online poll of 300 (answered by ewatrrr)

n a study of government financial aid for college students, researchers needed to... (answered by Boreal)

3. A telephone poll of 800 American adults asked "where would you rather go in your spare (answered by Boreal)

You wish to estimate with 95% confidence the population proportion of US adults who think (answered by jim_thompson5910)

1.We wish to estimate what percent of 18 to 25-year old's that own a Samsung phone. Out... (answered by math_tutor2020)

In a survey of 2383 U.S. adults, 1073 think that there should be more government... (answered by Boreal)

You want to estimate, with 95% confidence, the population proportion of U.S. adults who... (answered by stanbon)