I know there's a fairly good amount of Math and Stats guys out there, so let's try this. I was asking myself if it was accurate to use the Central Limit Theorem (confidence interval) to calculate the margin of error (say in pre-electoral polls) when there's more than two "serious options" (say >2 candidates with chances of winning). The margin of error on one percentage is calculated this way: +-2 ([p(1-p)]/n)^0.5. (19/20, hence the 2) But does it really makes sense to used a centric model (50-50 on each side of the curve)? Especially when there is >2 probable answers? Wouldn't some other probability law modeling, multidimensional or/and not centered, be more accurate? I'm probably confused on some point, I'm not very good at this. One hint that makes me think I'm just wrong somewhere is that this way of calculating only gives the margin of error in regards of the sample size, not other stuff. (But this begs the question, is there better ways?) Also, is there ways of calculating the margin of error that includes the different %? I've seen with one and two percentages but not more. My statistics and polls books/manuals are too introductory to help me on this, hence me asking Help?