$4.$ A forecaster is assessing two different models for demand. The output from each model and the actual demand data appear in the table. Use MAD and a tracking signal to compare the two models. Which model does a better job of forecasting?

Demand Model $1$ Model $2$

$5255\mathrm{.}051\mathrm{.}0$

$5254\mathrm{.}751\mathrm{.}9$

$6054\mathrm{.}452\mathrm{.}0$

$5655\mathrm{.}059\mathrm{.}2$

$5855\mathrm{.}156\mathrm{.}3$

$5855\mathrm{.}457\mathrm{.}8$

$5255\mathrm{.}658\mathrm{.}0$

$5755\mathrm{.}352\mathrm{.}6$

$5355\mathrm{.}456\mathrm{.}6$

$5755\mathrm{.}253\mathrm{.}4$