Khan Academy Static

A confidence interval for a proportion estimates what percent of a population fits some category based on a results from a sample. For example, if 70 adults own a cell phone in a random sample of 100 adults, we can be fairly confident that the true percentage in the population is somewhere between 61% and 79%. Go through this tutorial to learn how to calculate confidence intervals like this.

4628_Confidence_interval_example.html

4630_Margin_of_error_2.html

4629_Margin_of_error_1.html