A time series with forecast values and error terms is presented in the following table. The mean absolute deviation $($MAD$)$ for this forecast is $[[$Month$,$Actual,Forecast,$],[$July$,5,,],[$Aug$,11,5,6\mathrm{.}00],[$Sept$,13,6\mathrm{.}8,6\mathrm{.}20],[$Oct$,6,8\mathrm{.}66,-2\mathrm{.}66],[$Nov$,5,7\mathrm{.}862,-2\mathrm{.}86]]$