Final answer:
The reasonable definitions of the decision variables depend on the specific context of the problem, and it is important to carefully consider them to ensure accurate representation of the problem.
Step-by-step explanation:
Reasonable definitions of the decision variables are:
A) X11: household without children under 16 and without premium subscription, X12: household without children under 16 but with premium subscription, X21: household with children under 16 but without premium subscription, X22: household with children under 16 and with premium subscription.
B) X11: number of interviewed households without children under 16 and without premium subscription, X12: number of interviewed households without children under 16 but with premium subscription, X21: number of interviewed households with children under 16 but without premium subscription, X22: number of interviewed households with children under 16 and with premium subscription.
C) X11: cost of interviewing a household without children under 16 and without premium subscription, X12: cost of interviewing a household without children under 16 but with premium subscription, X21: cost of interviewing a household with children under 16 but without premium subscription, X22: cost of interviewing a household with children under 16 and with premium subscription.
D) All of the above are reasonable definitions. E) None of the above.
The reasonable definitions of the decision variables depend on the specific context of the problem. The choice of the most appropriate definition will be dictated by the information needed and the specific objective of the analysis. It is important to carefully consider the definitions of the decision variables to ensure accurate representation of the problem at hand.