On October 10, CBS News/YouGov released the results of a new poll, in which respondents from Pennsylvania were asked for whom they will vote: Democrat Hillary Clinton or Republican Donald Trump.
CBS News/YouGov poll results
The results show that 48.0% of participants indicated that they would cast a ballot for former Secretary of State Hillary Clinton, while 40.0% would vote for billionaire Donald Trump.
The poll was conducted from October 5 to October 7 among 997 likely voters. There is a sampling error of +/-4.2 percentage points. Considering this error margin, the gap between both candidates is statistically significant.
Putting the results in context
In general, however, a good strategy is to not have too much faith in the results of single polls, as they sometimes contain large errors. At least, one should examine how a poll's results compare to benchmark forecasts.
For the following comparison, we convert Trump's and Clinton's raw poll numbers into two-party vote shares. The resulting figures are 54.6% for Clinton and 45.5% for Trump.
Comparison to other polls
An average of recent polls in Pennsylvania sees Clinton at 55.3% of the two-party vote. Compared to her numbers in the CBS News/YouGov poll Clinton's poll average is 0.7 percentage points higher. This deviation is within the poll's margin of error, which suggests that the poll is not an outlier.
The poll in comparison with PollyVote's forecast
The most recent PollyVote anticipates Clinton to gain 53.0% of the two-party vote in Pennsylvania. Hence, Polly's forecast is 1.6 points below her polling numbers. The PollyVote forecast is thus in line with the poll's sampling error.