More about Perl version
Dependence over other Perl Modules
use Statistics::Descriptive;
use Math::CDF;
These are available at CPAN.
http://search.cpan.org/~colink/Statistics-Descriptive-2.6/Descriptive.pm
http://search.cpan.org/~callahan/Math-CDF-0.1/CDF.pm
use Poisson;
This is provided. Please make sure the "use lib" at the beginning of the scripts contains the correct path.