Answer:
A) paying your power bill
Explanation:
A. It is important to know the exact amount that you will pay for your power bill because if you pay an estimated amount you might underpay and have your power cut off or overpay and therefore use money that could have been used for other household expenses.
B. You cannot determine what the exact amount of bacon necessary for a salad will be. So you use the eye and preference, not exact calculations.
C. Without knowing the exact number of people who will attend the cookout it is impossible to order the exact amount of burgers. So you estimate and order a number you are comfortable with
D. As above, there is no way of knowing how many people will be at a rally, normally an estimate based on previous rallies and other factors is used