# T.DISTDAX Function (Statistical)

Returns the Student’s left-tailed t-distribution.

## Syntax

T.DIST ( <X>, <Deg_freedom>, <Cumulative> )
Parameter Attributes Description
X

The numeric value at which to evaluate the distribution.

Deg_freedom

An integer indicating the number of degrees of freedom.

Cumulative

A logical value that determines the form of the function. If cumulative is TRUE, T.DIST returns the cumulative distribution function; if FALSE, it returns the probability density function.

## Return values

Scalar A single decimal value.

The Student’s left-tailed t-distribution.

## Remarks

The Deg_freedom argument cannot be negative.

» 4 related functions

## Examples

```--  T.DIST    returns the Student's left-tailed t-distribution
--  T.DIST.2T returns the two-tailed Student's t-distribution
--  T.DIST.RT returns the right-tailed Student's t-distribution
--
--      T.DIST ( Value, DegFreedom, Cumulative )
--
--  https://en.wikipedia.org/wiki/Student%27s_t-distribution
DEFINE
VAR Vals            = GENERATESERIES ( 0, 5, 0.25 )
VAR DegFreedom      = 4.6
VAR CumulativeTrue  = TRUE   -- Cumulative distribution function
VAR CumulativeFalse = FALSE  -- Probability density function
EVALUATE
Vals,
"T Dist",            -- Probability density function
FORMAT (
T.DIST ( [Value], DegFreedom, CumulativeFalse ),
"#,0.0####"
),
"T Dist Cumulative", -- Cumulative distribution function
FORMAT (
T.DIST ( [Value], DegFreedom, CumulativeTrue ),
"#,0.0####"
),
"2T Dist",            -- Probability density function
FORMAT (
T.DIST.2T ( [Value], DegFreedom ),
"#,0.0####"
),
"RT Dist", -- Cumulative distribution function
FORMAT (
T.DIST.RT ( [Value], DegFreedom ),
"#,0.0####"
)
)
```
Value T Dist T Dist Cumulative 2T Dist RT Dist
0.0000000000 0.37961 0.5 1.0 0.5
0.2500000000 0.36572 0.59373 0.81253 0.40627
0.5000000000 0.32792 0.68085 0.6383 0.31915
0.7500000000 0.2757 0.75649 0.48702 0.24351
1.0000000000 0.21968 0.81839 0.36322 0.18161
1.2500000000 0.16789 0.86669 0.26662 0.13331
1.5000000000 0.12452 0.90305 0.1939 0.09695
1.7500000000 0.09054 0.92974 0.14052 0.07026
2.0000000000 0.06509 0.94903 0.10194 0.05097
2.2500000000 0.04657 0.96286 0.07428 0.03714
2.5000000000 0.03333 0.97275 0.05449 0.02725
2.7500000000 0.02393 0.97984 0.04031 0.02016
3.0000000000 0.01729 0.98495 0.0301 0.01505
3.2500000000 0.01259 0.98865 0.0227 0.01135
3.5000000000 0.00924 0.99136 0.01728 0.00864
3.7500000000 0.00685 0.99335 0.01329 0.00665
4.0000000000 0.00512 0.99484 0.01032 0.00516
4.2500000000 0.00387 0.99595 0.00809 0.00405
4.5000000000 0.00295 0.9968 0.0064 0.0032
4.7500000000 0.00227 0.99745 0.0051 0.00255
5.0000000000 0.00176 0.99795 0.0041 0.00205

## Related functions

Other related functions are:

Last update: Aug 3, 2024     » Show contributors

Contributors: Alberto Ferrari, Marco Russo

Microsoft documentation: https://docs.microsoft.com/en-us/dax/t-dist-dax

# 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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