Question

Pumpkin patch: Suppose we plant pumpkins in a garden where half of the plants are shaded. Then, to test a new fertilizer, we fertilize the plants in full sun and do not fertilize the plants in the shade. In the fall the fertilized plants yield more, bigger, and prettier pumpkins.Which of the following is the explanatory variable?A, Fall seasonB, FertilizerC, Pumpkin harvestD, Amount of sunshine

Answer 1

The correct answer is D, Amount of sunshine.

Indeed, fertilizer may or may not increase yields depending on many complex factors such as humidity, dryness, chemical balance, method of dispersion etc. However, it is an established biological principle that plants fare better with sunlight and in the absence of sunlight they yield less produce, whether they are fertilized or not.