from math import*
def paramvar(V,P):
  E=0;Var=0
  for i in range(len(V)):
     E=E+V[i]*P[i]
  for i in range(len(V)):
    Var=Var+(V[i]-E)**2*P[i]
  s=sqrt(Var)
  return [E,Var,s]