What is the Absolute percent error for perlod $4$ when Three period moving average forecast method is used $($Please round to $2$ declimal places for your answer$).$ Do Not corrert to percentage, leave as a decimal value.

The Following opens a blank Excel sheet, you only need to open it once: blank.ase

$\backslash$table$[[$Whet a$,$Trme sertes vibue,$],[$x$($Thme Period,ar Visales$),$Forecast,$*],[1,4\mathrm{.}8,,],[2,8\mathrm{.}3,,],[3,2\mathrm{.}9,,],[4,11\mathrm{.}0,,],[5,15\mathrm{.}2,,],[6,12\mathrm{.}2,,],[7,,,]]$