# CONFIDENCE

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 confidence interval for a population mean.

## Syntax

CONFIDENCE(*alpha*,*stdev*,*size*)

## Arguments

This function has these arguments:

| **Argument** | **Description** |
| -------- | ----------- |
| *alpha* | Alpha, significance level used in calculating confidence level, where confidence level is 100 times (1-*alpha*)% |
| *stdev* | Population standard deviation for the range |
| *size* | Number representing the size of the sample; if not an integer, the number is truncated |

## Data Types

Accepts numeric data for all arguments. Returns numeric data.

## Examples

`CONFIDENCE(0.5,B4,D5)`
`CONFIDENCE(0.5,R4C2,R5C4)`
`CONFIDENCE(0.05,3.5,150)` gives the result 0.560106363

## Version Available

This function is available in product version 1.0 or later.

## See Also

[AVERAGE](/spreadnet/docs/latest/online-formula/formulas-functionsall/formulas-functsAtoC/FunctionAVERAGE) \| [CHITEST](/spreadnet/docs/latest/online-formula/formulas-functionsall/formulas-functsAtoC/FunctionCHITEST) \| [Statistical Functions](/spreadnet/docs/latest/online-formula/formulas-overview/formulas-functs/formulas-functtypes/formulas-functsstats)