In aâ poll, 51â% of the people polled answered yes to the questionâ "Are you in favor of the death penalty for a person convicted ofâ murder?" The margin of error in the poll was 33â%, and the estimate was made with 94â% confidence. At least how many people wereâ surveyed? The minimum number of surveyed people was:

Respuesta :

Answer: 978

Step-by-step explanation:

Given : Prior proportion of the people polled answered yes to the question "Are you in favor of the death penalty for a person convicted of murder? : p=0.53

Margin of error : [tex]E=0.03[/tex]

Significance level : [tex]\alpha: 1-0.94=0.06[/tex]

Critical value : [tex]z_{\alpha/2}=1.88[/tex]

The formula to find the sample size is given by :-

[tex]n=p(1-p)(\dfrac{z_{\alpha/2}}{E})^2[/tex]

i.e. [tex]n=(0.53)(0.53)(\dfrac{1.88}{0.03})^2[/tex]

[tex]978.243377778\approx978[/tex]

Hence, the minimum required sample size =978