How'd you do on the quiz? Did the foot size throw you a little bit, making one example look taller or wider than its partner - with the same diameter and height? Adding a foot changes things visually so you need to be aware of what changing the diameter to foot ratio does to the look of your bowl. A small foot to diameter ratio makes the piece look kight and delicate, a larger foot to diameter gives the piece a more solid, stabile, functional look - visually adding mass.
Here are some examples for three popular Rule of Thumb Foot To Diameter Ratios. Notice which one seems most appropriate to you for each size example. Does One Size Fit All or does one work for a certain size range and another for larger pieces? There is no Right or Wrong here - this is just to get you seeing what looks right - to you - and using that awareness in your pieces.