Demystifying Sampling Error
Consider the following hypothetical newspaper excerpt:
An October poll of 800 registered voters found that, if the election were held that day, Candidate-X would beat Candidate-Y, 55% to 40%. While Candidate-X held a 15 point lead, his numbers have “slipped” from a September poll that showed Candidate-X at 58% and Candidate-Y at 39%.
Although data are [...]
