$($a$)$ Find the single force that is equivalent to the two forces shown. four$-$digit accuracy to minimize roundoff error. $N$

direction

$($counterclockwise from the $+x-$axis$)$

$($b$)$ Find the force that a third person would have to exert on the mule to make the net force equal to zero. four$-$digit accuracy to minimize roundoff error. $N$

direction

$($counterclockwise from the $+x-$axis$)$