I don’t understand why pollsters never do this
calculation. At this moment Nevada is
officially undecided. However 80% of
votes are cast with Obama leading 52 to Romney 46. From these numbers we can easily calculate
what percentage of voters Romney needs to take Nevada. Let’s first calculate the number he needs to
match Obama.

We can thing of this as the weighted average between the
votes already counted and those yet to be counted. This can be written out as the cast votes .8
and the uncast votes .2. a is the
proportion who vote Romney, (1-a) is the proportion that vote Obama. Everybody votes in this approximation.

.8 * .46 + .2 * a = .8 *.52 + .2*(1-a)

Now we need only solve for a.

P*R + (1-P)*a = P*O + (1-P)*(1-a)

P*R - P*O = (1-P)*(1-a) - (1-P)*a = (1-P)*(1-2a)

(P*R - P*O)/(1-P) = 1-2a

a = ½ - (R - O)/2
* P/(1-P)

R is Romney voters, O Obama and P is the proportional that
has already voted.

Using the previous example:

a = .5 - (.46-.52) * .8/.2

The above formula can be adjusted by making the totals into
proportions. I get Romney would need to
win 74 percent of the remaining Nevada votes to win. Probably unlikely.

A general formula can be defined as:

A general formula can be defined as:

P*R + (1-P)*a = P*O + (1-P)*(1-a)

Now let’s look at Florida.

Wednesday morning. This state is very close, just using a "1 percent" margin is not sufficiently accurate for me.

Wednesday morning. This state is very close, just using a "1 percent" margin is not sufficiently accurate for me.

PTotal = 4129360+4083321

R = 4083321 / PTotal

O = 4129360/ PTotal

Now we can easily calculate the P value from this. . Also,
we have 94% of districts reporting. Thus :

P=.97

So Romney only has a P value of .496175. Finally let’s plug in the values above.

a = .5 - (R - O)/2
* P/(1-P)

a = 1/2 - (R-O)/2 *
P/(1-P)

Thus we get that Romney would need win 59% of the remaining
votes to take Florida. This as opposed
to Nevada is possible though at this point unlikely.

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