Thank you for your help :)
I have just used randomize function with my random numbers generated by such thing"a:=stats[random,normald[0,1]](n):" and it helped.
I also tried to download maple9 update 9.03 and I found Listtools(I needed this package, sorry for mistake:)) package, but unfortunately I didn't found Statistics package. I also tried to find in maplesoft.com, but I didn't succes. I will try to find maple 10 or 11.