3.3.C—Calculate an appropriate confidence interval for a population proportion

Calculate an appropriate confidence interval for a population proportion.

• z denotes a critical value, such that z and z represent the boundaries enclosing the middle C% of the standard normal distribution, in which C% is an approximate confidence level with which the population proportion is estimated.
• An interval estimate can be constructed as point estimate (margin of error). For a population proportion, the one-sam p ple z-interval estimate is p 1 z n .