1 of 187 mil: Odds 7 of 18 states deviate beyond exit poll MOE to Bush

[TruthIsAll]

THE CLINCHER. 

SPIN THIS, PETER JENNINGS!

Another probability calculation which confirms the odds of
today's earlier post of 1 out of 250 million.

Well, not quite. It's 1 out of 187 million. 

Here's the calculation.

Let's calculate the odds that 7 out of 18 battleground states
would deviate OUTSIDE the margin of error and ALL go to Bush.

These are the Kerry exit poll and actual vote margins. 

Exit Poll	Actual BushGain
MO 	-8	-7	-1
CO	-7	-6	-1
AZ	-10	-10	0
MI	3	3	0
AR	-9	-9	0
IL	11	11	0
LA	-14	-15	1
IA	0	-1	1
NM	2	0	2
NV	-1	-3	2
ME	11	8	3

WI	5	1	4
OH	2	-2	4
PA	7	2	5
FL	1	-5	6
MN	10	3	7
NC	-4	-13	9
NH	17	1	16
	



Battleground States: 18 
Prob that a given state is outside the MOE and deviates to
Bush:2.50% 

Total number of states outside the MOE which deviated to
Bush: 7 

The calculation requires the BINOMIAL distribution: 

Probability (all 7 states outside MOE go to Bush)
= 1-BINOMDIST(7,18,0.025,TRUE)

= 0.000000533% 

or 1 out of 187,453,436 




 
 

[TruthIsAll]

1. ?

.

[kostya]

2. kick

:kick:

[T Roosevelt]

3. Which are the 7?

And just as a refresher, why binomial? And does the delta from the exit poll have any impact on the calculation?

[Awsi Dooger]

4. TruthIsAll, this is GARBAGE; you don't understand margin for error

Sorry to be so blunt, but it's accurate and therefore this mathematical exercise is worthless. Try finding a clincher that's not so easily spun into the toilet.

MOE is applied to EACH number, not just the MARGIN between the two candidates. You are making the most basic of mistakes, something network anchors and talking heads fall prey to repeatedly.

Let's look at this example, a hypothetical state poll, let's say Florida:

Kerry 50%
Bush 49%

Margin for error 4%

Now let's say Bush wins 52-47%. That is NOT outside the margin for error, despite the 6 point gap. The MOE is applied to EACH of the two numbers. Therefore, Kerry's support is expected to range from 46-54% and Bush from 45-53%. That is where the 95% confidence level kicks in. It is statistically more likely Kerry will be ahead by 1, and so on, than down 4 or 5 or 6, but all fall within the MOE.

Don't take my word for it. Look it up on the internet. Here is the first link in a search I just did: http://momentlinger.typepad.com/momentlingeron/2004/08/understanding_p.html

Besides using the most favorable exit polls for Kerry, like the absurd 57-41 edge in New Hampshire, and even if your initial use of MOE had been correct, you are also understating margin for error among state polls. You are obviously using 3%, based on where Ohio and Wisconsin fit on your list. The margins differed by 4%, yet are listed outside the margin for error on your list. The company that does nationwide exit polls states very clearly on their website that state exit polls include a 4% margin for error, not 3%: http://www.exit-poll.net/faq.html#a15

"What is the Margin of Error for an exit poll?
Every number estimated from a sample may depart from the official vote count. The difference between a sample result and the number one would get if everyone who cast a vote was interviewed in exactly the same way is called the sampling error. That does not mean the sample result is wrong. Instead, it refers to the potential error due to sampling. The margin of error for a 95% confidence interval is about +/- 3% for a typical characteristic from the national exit poll and +/-4% for a typical state exit poll. Characteristics that are more concentrated in a few polling places, such as race, have larger sampling errors. Other nonsampling factors may increase the total error."

[Name removed]

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[Awsi Dooger]

6. Pathetic capitalization and childish threats don't make you correct

You don't understand margin of error. Sorry. Take a course.

I noticed you didn't dare dispute the substantive points of my post -- that margin of error is NOT a simple "he won by 6 when the MOE was 4 and the poll said even."

Nor that you predictably used 3% as MOE is state polls when the exit poll website specifically indicated 4%. And don't pretend you didn't know that, because YOU PASTED A PARAGRAPH FROM THAT SAME FAQ IN A THREAD TWO DAYS AGO. That's selective analysis, precisely your style, completely misleading and about time someone called you out on it.

BTW, your first link leads nowhere. I wasn't surprised.

[Kurovski]

7. Go report it to the press.

accent on "go".

[Awsi Dooger]

9. Oh jeepers, sounds like you would vote yes in TIA's poll

And I have zero doubt I would "lose." That's one time TIA'a 99.99% would be correct.

His math is excellent. I've posted that many times. Far superior to mine. But IMO he uses it primarily to look backward and develop a flock of cynical worshippers on DU, much more than to provide a true assessment of probability.

That's a damn shame. If he focused more on demographic and electoral trends I think the math could be vital in improving this party's focus.

[Name removed]

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