In order to be a function we need one x-value corresponding to one y-value which is shown in the table. if we can have the same x value corresponding to multiple y values then it is no longer a function it is a relation.
You need to form an equation:
P+2/3P+1/2P=234
P+4/6P+3/6P=234
P+7/6P=234
13/6P=234
P=234/(13/6)
P=108
Height would be 21 inches, depth would be 5.