Question

Two students were testing the amount of fertilizer that would best promote the growth of tomato plants in a garden. Which of the following could be an unavoidable source of experimental error?

Select one:
a. variation of tomato plants
b. amount of water given to the plants
c. time given to the experiment
d. fertilization during the experiment

Answer 1

Think of it this way. Over which source would the experimenter have the least control?

Answer 2

a. variation of the tomato plants