This is a simple z score calculator that calculates the value of *z* (and associated *p* value) for two population proportions.

*Further Information*

The *z* score test for two population proportions is used when you want to
know whether two populations or groups (e.g., males and females; theists and atheists)
differ significantly on some single (categorical) characteristic - for example,
whether they are vegetarians.

*Requirements*

- A random sample of each of the population groups to be compared.
- Categorial data

*Null Hypothesis*

H0: p1 - p2 = 0, where p1 is the proportion from the first population and p2 the proportion from the second.

As above, the null hypothesis tends to be that there is no difference between the two population proportions; or, more formally, that the difference is zero (so, for example, that there is no difference between the proportion of males who are vegetarian and the proportion of females who are vegetarian).

*Equation*