in a poll 69 of the people polled answered yes to the questi

in a poll 69% of the people polled answered yes to the question , are you in favor of death penalty for convicted murders\"  The margin of error in the poll was 5% and the estimate was made with 96% confidence.  At least how many people were surveyed?

The minimum number of surveyed people was

Round up to nearest interger

Solution

Given a=1-0.96=0.04, Z(0.04/2)=Z(0.02)=2.05 (from standard normal table)

So n=(Z/E)^2*p*(1-p)

=(2.05/0.05)^2*0.69*(1-0.69)

=359.5659

Take n=360