PROBF Function

PROBF Function

Returns the probability from an F distribution

Category: Probability

See: 'CDF Function' on page 418

Syntax

PROBF ( x,ndf,ddf <,nc>)

Arguments

x

• is a numeric random variable.

• Range: x ‰

ndf

• is a numeric numerator degrees of freedom parameter.

• Range: ndf > 0

ddf

• is a numeric denominator degrees of freedom parameter.

• Range: ddf > 0

nc

• is an optional numeric noncentrality parameter.

• Range: nc ‰

Details

The PROBF function returns the probability that an observation from an F distribution, with numerator degrees of freedom ndf , denominator degrees of freedom ddf , and noncentrality parameter nc , is less than or equal to x . The PROBF function accepts noninteger degrees of freedom parameters ndf and ddf . If the optional parameter nc is not specified or has the value 0, the value returned is from the central F distribution.

The significance level for an F test statistic is given by

 p=1-probf(x,ndf,ddf); 

Examples

SAS Statements	Results
x=probf(3.32,2,3);	0.8263933602