The easiest way is to automatically generate the rule premise, using the Generate rules option in the FIS menu.
This option generates the rules corresponding to all possible combinations of the input MF variables: Degree and Yield, 4x3=12 rules in our case. Rule conclusions are initialized with a zero value, and must be modified.
Some of the generated rules can be simplified. This concerns Low degrees and very high yields. First remove the useless rules, then enter the rule conclusions in the Price column, as given in figure 2.