WorksheetFunction.T_Inv_2T Method
Returns the t-value of the Student t-distribution as a function of the probability and the degrees of freedom.
Namespace: Microsoft.Office.Interop.Excel
Assembly: Microsoft.Office.Interop.Excel (in Microsoft.Office.Interop.Excel.dll)
Syntax
'Declaration
Function T_Inv_2T ( _
Arg1 As Double, _
Arg2 As Double _
) As Double
'Usage
Dim instance As WorksheetFunction
Dim Arg1 As Double
Dim Arg2 As Double
Dim returnValue As Double
returnValue = instance.T_Inv_2T(Arg1, _
Arg2)
double T_Inv_2T(
double Arg1,
double Arg2
)
Parameters
Arg1
Type: System.DoubleProbability - The probability associated with the two-tailed Student t-distribution.
Arg2
Type: System.DoubleDegrees_freedom - The number of degrees of freedom with which to characterize the distribution.
Return Value
Type: System.Double
Remarks
If either argument is non-numeric, T_Inv_2T returns the #VALUE! error value.
If probability < 0 or if probability > 1, T_Inv_2T returns the #NUM! error value. If degrees_freedom is not an integer, it is truncated.
If degrees_freedom < 1, T_Inv_2T returns the #NUM! error value.
T_Inv_2T returns that value t, such that P(|X| > t) = probability where X is a random variable that follows the t-distribution and P(|X| > t) = P(X < -t or X > t).
A one-tailed t-value can be returned by replacing probability with 2*probability. For a probability of 0.05 and degrees of freedom of 10, the two-tailed value is calculated with T_INV_2T(0.05,10), which returns 2.28139. The one-tailed value for the same probability and degrees of freedom can be calculated with T_INV_2T(2*0.05,10), which returns 1.812462.
Note
In some tables, probability is described as (1-p).
Given a value for probability T_Inv_2T seeks that value x such that T_DIST_RT(x, degrees_freedom, 2) = probability. Thus, precision of T_Inv_2T depends on precision of T_Dist_RT(Double, Double). T_Inv_2T uses an iterative search technique. If the search has not converged after 100 iterations, the function returns the #N/A error value.