Objective

The objective is to compute a confidence interval for the proportion $p$ of a population that has some characteristic using a simple random sample from that population.

We choose a level of confidence that the interval contains the (unknown) population proportion $p$ , which we denote by $100\cdot(1-\alpha)$ .

This means that if we repeated the process of drawing the sample and calculating the confidence interval many times, we expect that $100(1-\alpha)$ percent of the time the interval will contain the true population proportion $p$ .