Refer to Exercise 14.23. In the description of this experiment, the researchers failed to note that the experiment in fact had been conducted at four different orange groves, which were located in different states. Grove 1 had a soil pH of 4.0, grove 2 had a soil pH of 5.0, grove 3 had a soil pH of 6.0, and grove 4 had a soil pH of 7.0. At each of the groves, three trees were randomly assigned to one of the calcium levels: 100, 200, or 300 pounds per acre. The data are given here.

a. How would this new information alter the conclusions reached in Exercise 14.23 concerning the effect of soil pH and calcium on the mean increases in tree diameter?
b. Design a new experiment in which the effects of soil pH and calcium on the mean increases in tree diameter could be validly evaluated. All four groves must be used in your design, along with the four levels of pH and three levels of calcium.

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Calcium Grove pH Value 4.0 5.0 6.0 7.0 100 200 300 5.2,5.9,63 74,7.0, 76 63,6.7, 6.1 7.1, 74.7.5 74.7.3, 7. 73, 7.5,72 76, 7.2. 74 7.6,7.5, 7.8 72, 7.3,7.0 72, 7.5, 7.2 7.4,7.0,6.9 68,6.6,6.4