If 2,000 card-carrying members of a political party were randomly sampled, and 1,600 said they wanted a change in leadership, what is the 95% confidence interval for the true population percentage for all of the card-carrying members of the party who wanted a change in leadership?
A) 78.2% to 81.8%
B) 78.0% to 82.0%
C) 76.5% to 83.5%
D) 77.7% to 82.3%
E) less than 50%

Question

Quizplus · Accepted Answer

The correct answer is A because the 95% confidence interval for the true population percentage is 78.2% to 81.8%. This means that we are 95% confident that the true population percentage of card-carrying members of the party who wanted a change in leadership is between 78.2% and 81.8%.

If 2,000 Card-Carrying Members of a Political Party Were Randomly