## How does the CONFIDENCE.NORM function (DAX) work?

As a type of statistical mean, the CONFIDENCE.NORM function is used to calculate and return the confidence interval for a population mean, using a normal distribution for a supplied probability and sample size.

## CONFIDENCE.NORM Formula Syntax

CONFIDENCE.NORM(
alpha,standard_dev,size
)

## How do you use the CONFIDENCE.NORM function?

This function is mostly used in financial data analysis to predict a wide range of financial goals. It is done by graphically mapping financial data into a set of variables.

## Considerations when using the CONFIDENCE.NORM function

This function has 3 arguments: the Alpha which is the significance level used to compute the confidence level, the Standard_dev which is the standard deviation for the data range, and the Sample Size.

If alpha ≤ 0 or alpha ≥ 1, CONFIDENCE.NORM returns the #NUM! error value.

If standard_dev ≤ 0, CONFIDENCE.NORM returns the #NUM! error value.

If size is not an integer, it is rounded.

If size < 1, CONFIDENCE.NORM returns the #NUM! error value.

If we assume alpha equals 0.05, we need to calculate the area under the standard normal curve that equals (1 – alpha), or 95 percent. This value is ± 1.96. The confidence interval is therefore:

## Formula examples using the CONFIDENCE.NORM function

=CONFIDENCE.NORM(A2,A3,A4)

CONFIDENCE.NORM(0.5,B4,D5)

=CONFIDENCE.NORM(C3,C4,C5)