SurveyMonkey 2012 Presidential Election Poll: Battleground State Analysis
Final 2004 Presidential Election Gallup Poll
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Transcript of Final 2004 Presidential Election Gallup Poll
![Page 1: Final 2004 Presidential Election Gallup Poll](https://reader035.fdocuments.in/reader035/viewer/2022072116/56813025550346895d95ab25/html5/thumbnails/1.jpg)
Final 2004 Presidential Election Gallup PollRhajiv Ratnatunga
STATS 1000 Seminar 21
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Polls are used by politicians and their supporters to gauge their likely election day performance.
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Gallup Statistical Model
“President Bush held a 49-47 edge over Sen. John Kerry when the undecided voters were not allocated to a particular candidate. When Gallup, using a statistical model that assumes that 9 of 10 of those voters would support Kerry, allocated the voters, the poll ended as a dead heat with each candidate garnering 49%.”
What does this mean?
This was the estimate
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95% Confidence Interval for Unknown Population Proportion
Estimate +/- margin of error
= sample proportion +/- 2 standard deviations
almost = to sample proportion +/- 2 standard errors
= p hat +/- 2 sqrt ((p hat (1-p hat))/n)
Explain the multiplierThe standard error
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Since the population proportion is unknown…..
The test for normal approximation is revised by….
Replacing the population proportion with the sample proportion
np becomes np(hat)
and
n(1-p) becomes n(1-p(hat))
Since n is big, we can say without doing calculations that both tests will be larger than 10
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Kerry/ Edwards
Bush/ Cheney
Nader/ Camejo
Other (vol.)
None (vol.)
No opini
on
Likely Voters
2004 Oct 29-31 ^† 47 49 * 1 * 3
Final Allocated Estimate
49 49 1 1 -- --
“Results based on likely voters are based on the subsample of 1,573 survey respondents deemed most likely to vote in the November 2004 General Election, according to a series of questions measuring current voting intentions and past voting behavior. For results based on the total sample of likely voters, one can say with 95% confidence that the margin of sampling error is ±3 percentage points.”
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.47 + 2 *sqroot ((.47(1-.47))/1573) = .495 = 50%
John Kerry -
.47 - 2 *sqroot ((.47(1-.47))/1573) = .444 = 44%
(44%,50%) = Confidence interval for Kerry
.49 + 2 *sqroot ((.49(1-.49))/1573) = .515 = 52%
George Bush
.49 - 2 *sqroot ((.49(1-.49))/1573) = .444 = .46%
(46%, 52%) = Confidence interval for Kerry
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The margin of error given was accurate.