In this post, we use the approximate confidence interval, as an interval estimate for [katex] p [/katex], where [katex] z [/katex] is the appropriate quantile for the standard normal distribution. This syllabus dot point is a part of the QCE Maths Methods course under the topic Interval Estimates for Proportions and the Normal Distribution and sub-part Confidence Intervals for Proportions.

[katex] ( \hat{p} – z \sqrt{ \frac{\hat{p}(1-\hat{p})}{n}}, \hat{p} + z \sqrt{ \frac{\hat{p}(1-\hat{p})}{n}}) [/katex]