Returns the twotailed Student’s tdistribution. The Student’s tdistribution is used in the hypothesis testing of small sample data sets. Use this function in place of a table of critical values for the tdistribution.
Syntax:= T.DIST.2T(x,deg_freedom)
The T.DIST.2T function syntax has the following arguments:
 X Required. The numeric value at which to evaluate the distribution.

Deg_freedom Required. An integer indicating the number of degrees of freedom.
Example: Let’s look at some Excel T.DIST.2T function examples and explore how to use the T.DIST.2T function as a worksheet function in Microsoft Excel:
Syntax: =T.DIST.2T(B1,B2)
Result: 0.295167235
Note:
 If any argument is nonnumeric, T.DIST.2T returns the #VALUE! error value.
 If deg_freedom < 1, T.DIST.2T returns the #NUM! error value.

If x < 0, then T.DIST.2T returns the #NUM! error value.