Question 174066
1. How much money should I set aside from each paycheck for groceries?


2. I'm going to build a concrete walkway from the street to my front door.  How much concrete should I order?


3. I want to remodel my bathroom.  How much will it cost?


In fact, for the given situations, an estimate is not only sufficient, it is the only sort of answer you will get.


The price of food at the supermarket is a variable and so is what a person eats from week to week, neither of which is exactly predictable, so budgeting for something like that can only be done by an estimate.


The amount of concrete needed for a project is based on a volume calculated from linear measurements -- and ALL measurements are approximate, even those that are extremely precise.  Hence, this situation is always answered by an estimate.


Asking a contractor for a price on a remodel job is based on his/her estimates.  It might be possible to exactly predict the cost of such a thing, if the job were not too complex, but the task of making that exact determination would require so much analysis and calculation effort that the cost of making the prediction would be many times more than the amount of any error in an estimate -- therefore not worth the trouble.