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To: FredZarguna
Actually, his interpretation is closer to the truth than yours, and in fact, your interpretation is incorrect.

Actually not Fred. The poll is statistically significant in that statistically speaking the race is a draw. There is no interpretation involved.

There is statistically NO DIFFERENCE between 0bama's percentages and Romney's percentages in this poll.

Right, which makes the poll statistically significant if one is happy with the methodology.

The sampling error at 95% confidence says that we can say with 95% confidence that the true vote for Romney lies between 40 and 48.6, and between 40.9 and 49.5 for 0bama.

Right, which is exactly what I said. CI means that 95 out of 100 random samples will fall between the error bars. That's it, it's statistics not rocket science.

That is not the same as your analysis, because these are NOT the true mean values of this statistic, they are sample means.

There are no mean values, sample means or otherwise. There is a sample with data. Sample means require values to find the mean. A poll is a single solitary sample with the associated data. There are no means, there are error bars at confidence intervals, in this case 95% because of the sample size.

For example: If the true mean really is Romney 48.6, 0bama 40.9, not only would we rarely see a sampling that gave us 0bama 49.5 - Romney 40, we can make a much stronger statement: with 95% confidence, we can say that we would NEVER see 0bama with 49.5 if his real statistic is 40.9. In that case, you could sample (random) populations a million times and find that with 95% confidence, 0bama doesn't get 49.5.

Outliers have a normal distribution above and below the error bars.

Sampling over and over again will NOT yield the same distribution centered at 44.3-45.2 -- which is what your example implies -- UNLESS AND ONLY UNLESS -- the TRUE poll result really is 44.3-45.2.

My "example" implies no such thing nor did I state it. Your inference is out of left field.

64 posted on 09/25/2012 5:12:22 PM PDT by jwalsh07 (.)
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To: jwalsh07
Sorry, I thought you understood statistics; my mistake. Yes, there are means. The %age quoted is a sample mean. If you don't understand that, you don't understand the theory of errors, which is where this comes from, so it's no wonder your post is so confused.
65 posted on 09/25/2012 5:44:21 PM PDT by FredZarguna ("The future does not belong to those who do not eat bacon.")
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