Answer
$\Delta m=1.045\ kg$
Work Step by Step
From table 4-2, the energy consumptions for a 68kg person will be aprroximately:
Jogging $540 Cal/h$, watching TV $72 Cal/h$
Proportionally for 80kg, the difference would be:
$\Delta \dot{E}=(540-72)\frac{80}{68}=550.59\ Cal/h$
Therefore the monthly difference (30 min a day) is:
$\Delta E=34,578.04\ kJ$
Assuming the difference would be used entirely to burn fat($e=33.1\ MJ/kg$):
$\Delta m=\Delta E/e$
$\Delta m=1.045\ kg$
