Answer:
The initial observation was that Gary was giving off a nasty slime and a stinking odor, which is slimotosis.
The independent variable was the treatment: rubbing seaweed on the Gary's shell and drinking Dr. Kelp.
The dependent variable was the amount of slime and the odor.
Spongebob's conclusion should be that the treatment worked but it is uncertain which treatment cured Gary because they were being tested at the same time.
