Construct and interpret an interaction plot for the data in Exercise 16.

Exercise 16

Vermont maple sugar producers sponsored a testing program to determine the benefit of a new fertilizer. A random sample of 27 maple trees in Vermont were chosen and treated with one of three levels of fertilizer. In this experimental setup, nine trees (three in each of three climatic zones) were treated with each fertilizer level and the amount of sap produced (in milliliters) by the trees was measured. The results are as follows.

Transcribed Image Text:

Low Fertilizer Medium Fertilizer High Fertilizer Southern Zone 76.2 80.4 74.2 88.0 94.1 93.0 84.2 87.5 83.1 Central Zone 81.4 85.9 86.9 98.2 94.7 96.2 90.3 89.9 93.2 Northern Zone 86.5 85.2 80.1 88.4 90.4 92.2 81.4 84.7 82.2