Compatibility - TDIST Function

The TDIST function replaces the T.DIST.2T & T.DIST.RT functions in Excel 2010.

Description

The function returns the Percentage Points (probability) for the Student t-distribution where a numeric value (x) is a calculated value of t for which the Percentage Points are to be computed. The t-distribution is used in the hypothesis testing of small sample data sets. Use this function in place of a table of critical values for the t-distribution.

Syntax

TDIST(x,deg_freedom,tails)

Arguments

Argument Description Required/ Optional
X The numeric value at which to evaluate the distribution. Required
Deg_freedom An integer indicating the number of degrees of freedom. Required
Tails

Specifies the number of distribution tails to return.

If Tails = 1, TDIST returns the one-tailed distribution.

If Tails = 2, TDIST returns the two-tailed distribution.

 Required

Notes

  • If Tails = 1, TDIST is calculated as TDIST = P( X > x ), where X is a random variable that follows the t-distribution. If Tails = 2, TDIST is calculated as TDIST = P(|X| > x) = P(X > x or X < -x)

  • The Deg_freedom and Tails arguments are truncated to integers.

  • If any argument is non-numeric, TDIST returns the #VALUE! error value.

  • If Deg_freedom < 1, TDIST returns the #NUM! error value.

  • If Tails is any value other than 1 or 2, TDIST returns the #NUM! error value.

  • If x < 0, then TDIST returns the #NUM! error value.

  • Since x < 0 is not allowed, to use TDIST when x < 0, note that TDIST(-x,df,1) = 1 – TDIST(x,df,1) = P(X > -x) and TDIST(-x,df,2) = TDIST(x,df,2) = P(|X| > x)

Example

TDIST Function
advanced_excel_compatibility_functions.htm
Advertisements