Levi decides to examine the effect of fertilizer on the growth of tomato plants. He chooses four plants for his experiment and a
pplies varying amounts of fertilizer to three of them. He does not apply fertilizer to one plant. Over a 15-day period, the plants receive fertilizer on Days 1, 4, 7, 10, and 13. Levi measures the height of all of his plants with a meterstick on Days 3, 6, 9, 12, and 15. He also makes sure to hold all experimental factors constant except for the fertilizer.
What is the dependent variable in Levi's experiment on tomato plants?
The measurement of the plant height. That (presumably) is dependent on the amount of fertilizer. Everything else is held constant (such amount of water, amount of sunlight, even distance from a window (constant heat), is held the same for all plants.
