1. When Perry's hot tub width changes from 1 to 2, length changes from 36 to 18, that is, a difference of 18 - 36 = -18.
When width changes from 2 to 3, length changes from 18 to 12, that is, a difference of 12 - 18 = -6 (different than -18).
Then, the lengths aren't changing in a linear fashion
2. the lengths are decreasing as follows:
36 - 18 = 18 units decreasing
18 - 12 = 6 units decreasing
12 - 9 = 3 units decreasing
9 - 6 = 3 units decreasing
