Question

A student wanted to look at plant growth in five different soil samples. he planted three of the same type of seeds in each of five identical containers and left them together in full sunlight. he gave each plant the same amount of water and charted the growth of each plant stem for three weeks. what is the independent variable in this experiment?

Answer 1

Answer: The soil

The experiment is using the same plant. The experiment also controls the water, sunlight, and the container. But it uses five different soil samples.
The independent variable in this experiment should be the soil because it is the variable that hopefully will influence the growth of the plants.