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

The CONFIDENCE.T function returns the value that you can use to construct the confidence interval for a population mean while using a Student’s t distribution.

## CONFIDENCE.T Formula Syntax

CONFIDENCE.T(
alpha,standard_dev,size
)

## How do you use the CONFIDENCE.Tfunction?

CONFIDENCE.T calculates the width of half the confidence interval. A value picked at random from the data set has 1-alpha probability of lying within the mean plus or minus the result of CONFIDENCE.T.

## Considerations when using the CONFIDENCE.T function

The CONFIDENCE.T function has 3 parameters: the Alpha which is used to compute the confidence level, the Standard_dev which is the population standard deviation for the data range, and the Sample size.

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

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

If size is not an integer, it is rounded.

If size equals 1, CONFIDENCE.T returns #DIV/0! error value.

## Formula examples using the CONFIDENCE.T function

=CONFIDENCE.T(0.05,1,50)

=CONFIDENCE.T( 0.05, 0.07, 100 )

=CONFIDENCE.T(0.05,STDEV(A2:A10),9)