Since the volume of a rectangular prism is V=lwh, we can isolate for h to obtain that h=V/(lw).
So, for the first prism, the height is 117/(4*6.5) = 4.5
Similarly, for the second prism, the height is 175.5/(6.5 * 4) = 6.75
So, the difference in heights is 6.75-4.5=2.25 = 2 1/4 inches
