Sara and Juan conducted an experiment to test which soil would be BEST for growing plants. They used sand, silt, and clay. They also made a mixture of soil using equal parts of sand, silt, and clay. They planted bean seeds in four pots and placed the pots in the sunlight. They watered the pots every day and tracked the seed germination and plant growth. At the end of the experiment, the seed in the pot of silt grew fastest. Which conclusion can be drawn from the experiment?