Calculate the torque $($in N $$ m$)$ about the z$-$axis that is out of the page at the origin in the following figure, given that

F$1=5\mathrm{.}0$ N$,$

F$2=3\mathrm{.}2$ N$,$

F$3=5\mathrm{.}0$ N$,$

F$4=2\mathrm{.}5$ N$.$

$($Indicate the direction with the sign of your answer.$)$