Given the demand and forecast values shown in the table below,

Period

Demand

Forecast

June

$495$

$484$

July

$515$

$506$

August

$519$

$528$

September

$496$

$506$

October

$557$

$550$

the mean absolute deviation $($MAD$)$ through the end of October is

Given the demand and forecast values shown in the table below,

Period

Demand

Forecast

June

$495$

$484$

July

$515$

$506$

August

$519$

$528$

September

$496$

$506$

October

$557$

$550$

the mean absolute deviation $($MAD$)$ through the end of October is

$1\mathrm{.}0$

$-1\mathrm{.}0$

$9\mathrm{.}2$

$-9\mathrm{.}2$