# ZTEST

Spread for WinForms provides advanced software components that support Excel import/export, full cell customization, an extensive calculation engine with over 450 functions and more, all with zero dependencies on Excel.

## Content



This function returns the significance value of a z-test. The z-test generates a standard score for x with respect to the set of data and returns the two-tailed probability for the normal distribution.

## Syntax

ZTEST(*array*,*x*,*sigma*)

## Arguments

This function has these arguments:

| **Argument** | **Description** |
| -------- | ----------- |
| *array* | Array of data to test |
| *x* | Value at which to test |
| *sigma* | [Optional] Known standard deviation for the population; if omitted, the calculation uses the sample standard deviation |

## Remarks

If sigma is not specified, the calculated standard deviation of the data in array is used.
The equation for calculating the z-test is as follows, where *n* is the number of data points.
![ZTEST Equation](https://cdn.mescius.io/document-site-files/images/0ed25d3e-6b2a-4cf0-8f1b-7ed5ab18cf12/artwork/func-ztest.png)

## Data Types

Accepts numeric data for all arguments. Returns numeric data.

## Examples

`ZTEST(A2:D12,40,0.877)`
`ZTEST(R2C1:R12C4,2)`
`ZTEST({5,10,15,12,11,8,16,7},10)` gives the result 0.355512703503418
`ZTEST({5,10,15,12,11,8,16,7},10,3)` gives the result 0.318675944098237

## Version Available

This function is available in product version 1.0 or later.

## See Also

[FTEST](/spreadnet/docs/latest/online-formula/formulas-functionsall/formulas-functsDtoG/FunctionFTEST) \| [TTEST](/spreadnet/docs/latest/online-formula/formulas-functionsall/formulas-functsTtoZ/FunctionTTEST) \| [Statistical Functions](/spreadnet/docs/latest/online-formula/formulas-overview/formulas-functs/formulas-functtypes/formulas-functsstats)