Calculate the total gross margin for wheat.

Here is the completed gross margin analysis:

Assumption for Item 1: The "Gross income product income" (Value per ha for item 1) is derived from the given Agent and Market commission values, which consistently point to R72,692.00. This implies the "Quantity" of "406" is incorrect for the given "Price per unit" and should be approximately 17.84 tons.

Gross income product income

1. Value per ha: $$$$