Make a statement that describes the anatomical position of the heart
in relation to other organs and structures in the thorax. Your answer
should use terms like anterior, superior, medial

This may be helpful (scroll down to "heart"):

http://www.bartleby.com/107/284.html

Do you mean in cats, rabbits, snakes, fish, frogs, squid...?

Sorry, in humans.

The heart sits profoundly in the chest within the mediastinum, medial
to the two lungs.  It is posterior (dorsal in quadrupeds) to the
sternum, anterior (ventral in quadrupeds) to the vertebral column and
superior (cranial in quadrupeds) to the diaphragm. Two thirds of the
heart is located to the left of the midsagittal plane, and one third
is located to the right.