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,degrees_freedom,tails)
X is the numeric value at which to evaluate the distribution.
Degrees_freedom is an integer indicating the number of degrees of freedom.
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.
Remarks
-
If any argument is nonnumeric, TDIST returns the #VALUE! error value.
-
If degrees_freedom < 1, TDIST returns the #NUM! error value.
-
The degrees_freedom and tails arguments are truncated to integers.
-
If tails is any value other than 1 or 2, TDIST returns the #NUM! error value.
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TDIST is calculated as TDIST = p( x<abs(X)), where X is a random variable that follows the t-distribution.
Examples
|
X |
Degrees |
Formula |
Description (Result) |
|
1.96 |
60 |
=TDIST([X],[Degrees],2) |
Two-tailed distribution (0.054644927 or 5.46 percent) |
|
1.96 |
60 |
=TDIST([X],[Degrees],1) |
One-tailed distribution (0.027322463 or 2.73 percent) |
