Answer
$18.9\%$ of the person's height along line from shoulder to hand.
Work Step by Step
$x_{CM}=$
$\frac{(6.6kg)(81.2m-71.7m)+(4.2kg)(71.7m-55.3m)+(1.7kg)(55.3m-43.1m)}{6.6kg+4.2kg+1.7kg}=0.189m$
$0.189m\times100\%=18.9\%$ of the person's height along line from shoulder to hand.