You are relaxing at your South Pacific vacation home when you notice a huge number of fruit bats feeding in three nearby fruit trees of different sizes. The number of fruits on the trees varies with the volume of the crown of the tree (that is, the upper part of the tree that contains branches and leaves). The largest tree has 168 fruits on it, the middle-sized one has 84, and the small one has 42. Thinking back to your animal behavior class, you guess that the bats will have the same GUD per tree. Eventually the bats do leave and you go out and find you were right. What did you observe