# The Excel function: Z.TEST

## Syntax

Z.TEST(array,x,[sigma])

The Z.TEST function syntax has the following arguments (argument: A value that provides information to an action, an event, a method, a property, a function, or a procedure.):

**Array**Required. The array or range of data against which to test x.**x**Required. The value to test.**Sigma**Optional. The population (known) standard deviation. If omitted, the sample standard deviation is used.