A poll taken of 500 voters three months before the election showed that 55% favored the Republican candidate with a margin or error of 4%. A second poll of 500 voters taken two weeks later showed that 45% favored the Republican candidate, again with a margin of error of 4%. Consider the following possible explanations for these results.
"1) At least one of the polls is wrong since the ranges of possible values of the population
Parameter do not overlap."
2) Both polls are right, but voters changed their minds between the two polls.
"3) One of the polls selected a sample that was not representative of the population.
Which statements are possible explanations of the results?"

Question

Quizplus · Accepted Answer

The results could be explained by voters changing their minds (statement 2) or by one of the polls having a non-representative sample (statement 3). The ranges of possible values do overlap when considering the margin of error, so statement 1 is incorrect.

A Poll Taken of 500 Voters Three Months Before the Election