use Statistics::Basic qw(stddev);

#generate a lot of random numbers, by the preferred way, ie: 

for (1..1000){
   $number1= int(rand(100000000));
   push @listofnumbers1, $number1;}

my $stddev1 = stddev(@listofnumbers1);

#repeat the process
push @listofnumbers2, $number2;
my $stddev2 = stddev(@listofnumbers2);