A gardenerwould like toknow if the weight of her parsley plants is influenced by using fertilizer. She selects 90 plants and randomly divides them into three groups of 30 plants each. She then applies an organicbiological fertilizer to the first group, a chemical fertilizer to the second group, and no fertilizer at all to the third group. The results are displayed in the three histograms below:

Fertilizer used for parsley plant None Biological Chemical 5 Frequency O 30 40 50 60 70 80 30 40 50 60 70 80 30 40 50 60 70 80 Weight in grams of parsley plant