In a survey, the planning value for the population proportion is p* = .35. How large a sample should be taken to provide a 95% confidence interval with a margin of error of .05?
Im really having trouble finding an answer for this problem with the information that has been given, please help me understand the process in which to solve this type of problem! :(
Im really having trouble finding an answer for this problem with the information that has been given, please help me understand the process in which to solve this type of problem! :(
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A 95% CI for the population proportion is
p*-1.96sqrt(p*(1-p*)/n)
the margin of error is 1.96sqrt(p*(1-p*)/n).
Sub p*=0.35 ,equate to 0.05 and solve for n giving
n correct to a suitable accurfacy. (350 will do nicely)
p*-1.96sqrt(p*(1-p*)/n)
Sub p*=0.35 ,equate to 0.05 and solve for n giving
n correct to a suitable accurfacy. (350 will do nicely)