Answer
$U_{grav} = 420~J$
This energy comes from the work done by the ground on the person during the jump.
Work Step by Step
$U_{grav} = mgy = (72~kg)(9.80~m/s^2)(0.60~m)$
$U_{grav} = 420~J$
This energy comes from the work done by the ground on the person during the jump.
