A z-test is a hypothesis test for statistical significance between two sample proportions. Before it can be conducted, it must meet the conditions for inference for a z-test. conditions for inference (z-test) has to be random has to be reasonably normal (vis a vi test for normality) each sample has to be independent (or 10% rule) use a z-statistic to find p-value Given a sample proportion, calculate the sample proportion standard deviation (given on the formula sheet) Then, divide the difference between measured and null proportions to figure z that is,
\begin{equation} z = \frac{\hat{p}-p_0}{\sqrt{\frac{p_0(1-p_0)}{n}}} \end{equation}
Look up the probability of z taking place on a z table. Then, 1-z would yield the p vaule.