def topRange(l, s):
  """
  Given a list of values, determines a range in which the values in the top 
  s% must lie.

  Args:
    l: A list of values
    s: A percentage
  Return:
    A tuple (lowest value that could be in top s%, max value in l)
  """
  mx = max(l)
  mn = min(l)
  if s is 100:
    return (mn, mx)
  dx = (mx - mn) / 100.0      # Width of 1% in the range covered by l's vals
  min_thresh = mx - (s * dx)  
  return (min_thresh, mx)