The Excel TINV function calculates the inverse of the two-tailed Student’s T Distribution, which is a continuous probability distribution that is frequently used for testing hypotheses on small sample data sets.
Syntax: TINV( probability, degrees_freedom )
Where the function arguments are listed in the table below:
|probability||–||The probability (between 0 and 1) for which you want to evaluate the inverse of the Student’s T Distribution.|
|degrees_freedom||–||The number of degrees of freedom (must be ≥ 1)|
Note that the Excel Tinv Function calculates the inverse of the two-tailed Student’s T Distribution. – if you want to calculate the inverse of the one-tailed t-distribution you can simply double the probability. ie. The one-tailed inverse Student’s T Distribution = TINV( 2*probability, degrees_freedom ).
Tinv Function Examples
The chart on the right shows the 2-tailed Inverse Student’s T Distribution with 10 degrees of freedom.
If you want to calculate the value of this function for a probability of 0.25, this can be done using the Excel Tinv function, as follows:
=TINV( 0.25, 10 )
This gives the result 1.221255395.
If you want to calculate the value of the one-tailed inverse Student’s T-Distribution for a Probability of 0.25, this can be done by doubling the probability, as follows :
=TINV( 0.5, 10 )
This gives the result 0.699812061.
Tinv Function Errors
If you get an error from your Excel Tinv function this is likely to be one of the following :
|#NUM!||–||Occurs if either The supplied probability argument is < 0 or > 1 or the supplied degrees_freedom argument is < 1|
|#VALUE!||–||Occurs if either of the supplied arguments are non-numeric|