In a survery reported in Newseek, 43% of respondents answered 'yes' to the question "Do you believe dreams reflect unconscious desires?" How many respondents are needed for the survey to have margin of error 2.5%?
N=(1.96 / m)^2 * p (1 - p)
N= (1.96 / .025)^2 * (.43) (1-.43)=
6146.56 (.43) (.57)=
2643.021 (.57)=
1506.522=
1506 people
N=(1.96 / m)^2 * p (1 - p)
N= (1.96 / .025)^2 * (.43) (1-.43)=
6146.56 (.43) (.57)=
2643.021 (.57)=
1506.522=
1506 people