Functions and CALL Routines

PROBT Function

Returns the probability from a t distribution.

Category:	Probability
See:	CDF Function, PDF Function

Syntax
Arguments
Details
Examples
See Also

Syntax

PROBT(x,df<,nc>)

Arguments

x

is a numeric random variable.

df

is a numeric degrees of freedom parameter.

Range:

df > 0

nc

is an optional numeric noncentrality parameter.

Details

The PROBT function returns the probability that an observation from a Student's t distribution, with degrees of freedom df and noncentrality parameter nc, is less than or equal to x. This function accepts a noninteger degree of freedom parameter df. If the optional parameter, nc, is not specified or has the value 0, the value that is returned is from the central Student's t distribution.

The significance level of a two-tailed t test is given by

p=(1-probt(abs(x),df))*2;

Examples

SAS Statements	Results
x=probt(0.9,5);	0.7953143998