Question $1$

The table below shows actual Demand, and a Forecast of the Demand.

Period

$1$

$2$

$341$

$437$

$545$

Demand, $D_t$

$37$

$40$

$37\mathrm{.}00$

$37\mathrm{.}90$

$38\mathrm{.}83$

$38\mathrm{.}57$

Calculate the Mean Absolute Deviation $($MAD$).$ Answer to $2$ decimal places.