How can a poll of only 1,004 Americans represent 260 million people with only a 3 percent margin of error?
488365
Try again Paul C.  The population doesn't need to look normal.\n\nThis all comes down to the Central Limit Theorem.  Let's assume that I take many samples of size 1004 from the population.  Well, each sample will have a percentage that is different from the population percent, because samples are going to look different from the population.  Also, each sample is going to look different from each other, because they are different samples.  If we were to draw a graph that looked at the "behavior" of these many samples, we would notice the following:\n\n1.  If I were to average out all of these sample percents, I would get the population percent.  Hopefully you can see why this would happen.  Sample percents will be around the population percent, but just be off by a little bit.\n\n2.  If I were to look at the spread of the percents, the spread would be smaller as bigger samples were taken.  In other words, if I had taken samples of size 500, the sample percents would be more spread out than for samples of size 1004.  That is because if were take larger samples, then we have more information about the population, so we should expect to get closer to the population percent.\n\n3.  As I take larger and larger samples, the shape of the graph of sample percents would look more and more like a normal curve.  A normal curve is shaped like a bell, where the middle of the bell is were the population percent is.\n\nSo Paul C, it doesn't matter that the population doen't look normal; all we need is a sample that is large enough.\n\nNow the margin of error on polls is typically going to be\n\n2*sqrt(p(1-p)/n))*100%\n\nwhere p is the sample proportion (the sample percent divided by 100%) and n is the sample size.  It can be shown that this margin of error would be at its largest if p = 0.5, so the largest the margin of error would be in this case would be\n\n2*sqrt(0.5*0.5/1004)*100% = 3.2%\n\nThis is typically associated with 95% confidence.  This basically means that if I were again to take many, many samples of size 1004,  95% of the sample percents would be within a margin of error away from the true population percent.\n\nThis of course depends on the sample that is taken.  The online polls that you see would not be good estimates for the population percent.  Below I have a link to a story that MSNBC has on each of its online polls.  The title is "How 1,000 people can be more representative than 200,000."  I think that it is a very good explaination of this topic.
343589
I just asked everyone (all 6 billion of them) and the answer is 37.83%.  38% like him, 13% are neutral, and 11% don't care.  I'm in the last group.
333142
Not even close - for a start, how can 2 parties represent the views of all the people in one of the largest countries in the world?  Especially when the head of state is not elected directly by the people, but by an Electoral College.  It seems absurd that a President can come to power who, when the actual votes of the people are counted, didn't win?  Surely those are the votes that count?  You have one of the most culturally diverse populations on the planet, and yet your Parliament, Government and Judiciary are predominantly white, middle class, wealthy and male.  That doesn't sound very democratic to me.
1187194
i've seen a lot of responses that say it's because so smaller states have a say. what nonsense!!\nwe have the "college" because our democracy is a farce. a popular vote means whoever receives the most votes wins. we, the american people aren't trusted to vote in a president. it is decided by our "betters". a popular vote is the only way a true democracy can function. that's why our's is broken. and needs fixing badly.
321604
I haven't been able to find any exact numbers, but since you asked for fraction, it's about 1/3 or about 2 billion people.
173329
okay now I read you. Public opinion is just that. Opinion of the public. And the American people are not by any means the same all the way through. People's opinions differ all the time no matter what it is. Remember after 9/11 and the whole country was behind invading Afganistan? Well there probably was 5% of Americans not gun-ho about it.\n\nAnd thats the beauty of America. Its what our founding fathers would want to see. Not a single minded entity, but a multi-faceted body of individuals with different opinions on a mutlitude of issues.
620035
do the representatives of any state represent the general population of their state?\n\nregarding voting, your rep., rep's the majority that voted.
516140
As a Lying red-necked twirp, just like MOST americans do.\nHe is not an IDIOT, he's an intellectual celibate.\n\nHowever, most of the world sees Americans as 300 million \nG Dumbya's running around in our pickup with a gun rack. \nSince we are void of any grammatical skills and can not say any word with more than 1 syllable without difficulties and maintain coherent thought.\n\nOh well, we can't blame them we allowed him to steal the election not once but twice.
1125349
about 20% of the electorate.\nSo thats 40% of the actual votes.
900722
Could be, some of the toss-up states (e.g. VA) are within a thousand votes.  Close enough to count the absentee ballots.
801986
You cannot, as the individual biases of the people affect the poll.\n\nWhat you are looking for is a poll that represents the people, not one that is unbiased.  For that, you need a large sample.  If you were doing a poll involving a town of 500, talk to at least 350 people.  If you were doing a state, that number would be much larger.\n\nA poll is to show the opinions of the people, not to be unbiased.  So you  need a large sample of the group you are targeting to get a good poll.
286954
Because someone has to be here to draw the line for you, EVERYTHING can not be your favorite\nStatistics show that most Americans only have 17 Favorites so they gave you alot of leeway.
569622
It is hard to prove you wrong when you are right, and I hate it when somebody else it right. Yours is a good observation shared by 70% of the people in the United States and probably the numbers are higher over seas.
677859
Because Americans will not stand up and band together and speak their minds. Those that do, cannot generate enough support because people have no back bone. Do you think for one second that if you were a Pres. say of a company, and your ratings were 30% or less that you would still be Pres.? NO. There should be no differences. Arm yourself with knowledge and VOTE!! Just a note.. 1 in 3 Republicans do not want BUSH in office at this point of his Presidency. What does that tell you??
522550
USA rounds it's numbers - 90% is a bit too low -it's actually 93%
912573
Blessed:  That is a good question.  I often wonder the same thing.  The comments others have made here identify differences.  But I too wonder how this country can split so evenly in most elections.  It is rare for most candidates to win more than 55% of the votes.\n\nI would add to the list of factors:  many Americans are poorly informed about issues and how our economy works.  They are easily misled by perverse campaign strategies that focus on issues with little impact on the average citizen's life.
1127766
61 Million votes\n\nThat's how.