# CONFIDENCE.NORMDAX Function (Statistical)

Returns the confidence interval for a population mean, using a normal distribution.

## Syntax

CONFIDENCE.NORM ( <Alpha>, <Standard_dev>, <Size> )
Parameter Attributes Description
Alpha

The significance level used to compute the confidence level. The confidence level equals 100*(1 – alpha)%, or in other words, an alpha of 0.05 indicates a 95 percent confidence level.

Standard_dev

The population standard deviation for the data range and is assumed to be known.

Size

The sample size.

## Return values

Scalar A single decimal value.

## Remarks

The confidence interval is a range of values. Your sample mean, x, is at the center of this range and the range is x ± CONFIDENCE.NORM. For example, if x is the sample mean of delivery times for products ordered through the mail, x ± CONFIDENCE.NORM is a range of population means.

## Examples

```--  CONFIDENCE.NORM returns the confidence interval
--  for a population mean, assuming a normal distribution
--  CONFIDENCE.T uses a Student's T distribution instead
--
--      CONFIDENCE.NORM ( Alpha, StandardDev, SampleSize )
--
--  Confidence level equals 100*(1-alpha)%
--  Alpha 0.05 indicates a 95% confidence level
DEFINE
TABLE SampleData = { 2, 4, 4, 4, 5, 5, 7, 9 }
VAR Mean         = AVERAGE ( SampleData[Value] )
VAR StandardDev  = STDEV.S ( SampleData[Value] )
VAR SampleSize   = COUNTROWS ( SampleData )
VAR Alpha        = 0.05 -- 95% confidence level
EVALUATE
{
( "AVERAGE",          Mean ),
( "STDEV.S",          StandardDev ),
( "CONFIDENCE.NORM",  CONFIDENCE.NORM ( Alpha, StandardDev, SampleSize ) ),
( "CONFIDENCE.T",     CONFIDENCE.T    ( Alpha, StandardDev, SampleSize ) )
}

```
Value1 Value2
AVERAGE 5.00
STDEV.S 2.14
CONFIDENCE.NORM 1.48
CONFIDENCE.T 1.79

Last update: Sep 28, 2022     » Show contributors

Contributors: Alberto Ferrari, Marco Russo

Microsoft documentation: https://docs.microsoft.com/en-us/dax/confidence-norm-function-dax

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# Context Transition

This function performs a Context Transition if called in a Row Context. Click to read more.

# Row Context

This expression is executed in a Row Context. Click to read more.

# Not recommended

The use of this function is not recommended. See Remarks and Related functions for alternatives.

# Not recommended

The use of this parameter is not recommended.

# Deprecated

This function is deprecated. Jump to the Alternatives section to see the function to use.

# Volatile

A volatile function may return a different result every time you call it, even if you provide the same arguments. Click to read more.

# Deprecated

This parameter is deprecated and its use is not recommended.

# DirectQuery compatibility

Limitations are placed on DAX expressions allowed in measures and calculated columns.
The state below shows the DirectQuery compatibility of the DAX function.

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