A student studied the effect of different plant hormones on the growth of corn seedlings of the same height and species. The student took six groups of 10 plants each. All initial heights were 1 cm. She gave one group water and the other groups the same amount of water with 1.00 micrograms of different hormones mixed in per mL of water. At the end of the 15 days, she measured the height of each seedling, averaged the results, and recorded them below.