6.26 In the corn field. An agronomist (a specialist in crop production and soil chemistry) wants to compare the yield of four corn varieties. The field in which the experiment will be carried out increases in fertility from north to south. The agronomist therefore divides the field into 20 plots of equal size, arranged in five east-west rows of four plots each, and employs a block design with the rows of plots as the blocks.
(a) Draw a sketch of the field, divided into 20 plots. Label the rows Block 1 to Block 5.
(b) Do the randomization required by the block design. That is, randomly assign the four corn varieties A, B, C, and D to the four plots in each block. Mark on your sketch which variety is planted in each plot.