# Documentation/Calc Functions/T.INV.2T

T.INV.2T

## Category:

Statistical Analysis

## Summary:

Calculates the two-tailed inverse of the Student's t-distribution. It finds the value of a random variable for which the two-tailed test value for the Student's t-distribution would be equal to a particular probability.

## Syntax:

T.INV.2T(Number; DegreesFreedom)

## Returns:

Returns a positive real number which is the inverse of the specified two-tailed test value for the given Student’s t-distribution.

## Arguments:

Number is a real number between 0(exclusive) to 1(exclusive) or a reference to a cell containing that number which is the two-tailed test value for which the inverse is to be calculated.

DegreesFreedom is a positive integer value or a reference to a cell containing that value which is the number of degrees of freedom for the Student's t-distribution.

• If Number is less than or equal to 0 or greater than or equal to 1 then the function returns an error value.
• If DegreesFreedom is less than 1 then the function returns an error value.
• If DegreesFreedom is a non-integer value then the function uses its floor value, i.e. it is truncated to an integer.

• It is such that if T.DIST.2T(x;df) = p or TDIST(x, df, 2) =p then T.INV.2T(p;df) = x.

## Examples:

Formula Description Returns
=T.INV.2T(0.8;8) The function calculates the two-tailed inverse of the Student's t-distribution. Here we can see that T.DIST.2T(0.261921096748832;8) gives 0.8. 0.261921096748832
=T.INV.2T(0.1;8) The function calculates the two-tailed inverse of the Student's t-distribution. Here we can see that T.DIST.2T(1.8595480375309;8) gives 0.1. 1.8595480375309
=T.INV.2T(1;8) The function calculates the two-tailed inverse of the Student's t-distribution. Here we can see that T.DIST.2T(0;8) gives 1. 0
=T.INV.2T(0;8) The function returns an error value when Number is either less than equal to 0 or greater than 1. Err:502

T.DIST.2T

T.DIST.RT

T.DIST

TINV

T.TEST

TDIST

T.INV

TTEST

None

T.INV.2T