MATH 376 -- Probability and Statistics 2
The F-distribution describes the distribution of a
ratio of two
- distributed random variables, scaled
by the numbers of degrees of freedom of each: If
is
(
) and
is
(
) , then the ratio
has an F-distribution with
``
numerator
degrees of freedom'',
and
``
denominator degrees of
freedom''. F-distributions are always skewed, with
expected value between 0 and 1:
> | read "/home/fac/little/public_html/ProbStat/MaplePackage/MSP.map"; |
> | plot([y->FPDF(3,4,y),y->FPDF(5,20,y),y->FPDF(7,300,y)],0..5,color=[red,blue,black]); |
> |