Z-tests are crucial statistical procedures to test for claims about population parameters using the normal distribution. We can use for one population or two population means provided that the population standard deviations are known. Also, we can use a z-test to test for claims about a population proportion.

Also, via the Central Limit Theorem, the z-test can be used as an approximation by many statistical procedures (parametric and non-parametric).

In this page you will all the Z-tests we have available. Check the list below:

## Z-test for One Population Mean

## Z-test: One Population Proportion

## Z-test for two Means, with Known Population Standard Deviations

## Z-test for Two Proportions

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