1. Population Proportion The fraction of values in a population which have a specific attribute p = Population proportion X = Number of items having the attribute N = Population Size

2. Sample Proportion The fraction of items in a sample that have the attribute of interest p = x / n p = Sample proportion x = Number of items in the sample with the attribute n = Sample size

3. Sampling Distribution of Proportion In many instances, the objective of sampling is to estimate a population proportion. In all instances, the decision makers could select a sample, compute the sample proportion, and make their decision based on the sample results. If the sample size is sufficiently large, the normal distribution can be used as a reasonable approximation to the discrete binomial distribution.

4. Sampling Distribution of p Provided we have a large enough sample size, all the possible sample proportions will be approximately normally distributed with Standard Error

5. Confidence Interval for the Population Proportion