1. Suppose we were interested in knowing how the amount of fertilizer influences the corn yield. The yield per plot in bushels of corn was observed on 10 plots that had been fertilized in varying degrees. The data are given in the following table: Yield (in bushels) Fertilizer (in pounds) 12 13 13 14 15 15 14 16 17 18 x; = 40, Ey: = 147, Ex7 = 180, Ey7 = 2 193, Exy = 6112. Refers to question 1. Use the graphs to check the validity of the model assumptions. Clearly state which assumption the graph is used to check and whether the assumption is violated or not, and why. eld = 10,1 +1.15 fertilizer 1.0 IN 10 Asq 0.8340 AdjRaq 0.5 0. 8020 0. 8404 0.0 05 + -1.0 1.5 -20 120 12.5 13.0 13.5 140 14.5 15.0 15 5 16.0 16.5 17,0 Predicted Value