Answer: 3295
Step-by-step explanation:
We know that the formula we use to find the sample size , if prior proportion is available :-
[tex]n=p(1-p)(\dfrac{z_{\alpha/2}}{E})^2[/tex]
Given : The approx proportion of registered voters who support the measure is : p= 0.58
Margin of error : E=0.02
Critical value for 98 percent confidence : [tex]z_{\alpha/2}=2.326[/tex]
Required sample will be :
[tex]n=(0.58)(1-0.58)(\dfrac{2.326}{0.02})^2=3294.858084\approx3295[/tex]
Hence, You need to sample 3295 registered voters in order to be 98% confident that your estimate is not off my more than 2%.