***Margin of error for Obama = sqrt[(.498*(1-.498))/976] = .0016
scale it by 100 to convert to percent and multiply by 2 to get 95% CI
McCain's 43.9% is outside the 95% confidence interval of 46.6 to 53, thus, we conclude
that Obama has a statistically significant lead as of this early October poll.
A lot can happen in the last month, but we could use this result as one of many possible predictions for popular vote.
*Obama's lead is statistically significant at p<.05
Note: I have actual access to the poll and used SPSS to do this analysis.