26. In a biological experiment 4 concentrations of a certain chemical are used to enhance the growth of certain type of plant over a specified period of time. The following growth data, in centimeters, were recorded for the plants that survived: Concentration 2 3 4 8.2 7.7 6.9 6.8 8.7 8.4 5.8 7.3 9.4 8.6 7.2 6.3 9.2 8.1 6.8 6.9 8.0 7.4 7.1 6.1 Is there a significant difference in the average growth of these plants for the different concentrations of the chemical? Use a 0.01 level of significance