function out = s104021103()
  format long;
  x = [0.3, 0.4, 0.5, 0.6];
  exp = [0.5488, 0.4493, 0.3679, 0.3012];
  y = x - exp;
  Q = zeros(4);
  Q(:,1) = x';
  z = 0;
  for i = 1 : 3
    for j = 1 : i
      Q(i+1,j+1) = ( (z - y(i-j+1))*Q(i+1, j) - (z - y(i+1))*Q(i,j) ) / (y(i+1) - y(i-j+1));
    end
  end
  out = Q(4,4)
end