Create a complete $C$ program that includes all necessary functions in order to determine the electricity costs associated with a certain apartment building in each area. Each apartment's electricity consumption for the specified number of days is listed in a file named ElectricConpumption.txt$.$ and the number of days related to each consume is contained in the file Days.txt $($For instance, if the first line of ElectriicConsume.txt includes $157$ and the first line of Days.txt contains $15,$ then $157$ Kilowatts of energy were spent over a period of $15$ days$).$ The program's goal is to find out how much energy each apartment will cost based on how many kilowatts are used and how much a kilowatt costs. The program's second objective is to calculate each apartment's electricity consumption in KW using the average consumption of all units.

The program should use different functions, such as follows:

Function designed to determine each apartment's exact electricity costs before taxes depending on the cost per kilowatt.

Function created to determine the exact fees after taxes by adding the tax value based on consumption value to the amount of consumption reported on ElectricConsumption.txt$.$

Function designed to calculate the Approximate Electric consumption based on the total number of days and total electric consumed for all apartments.

Function that indicates how the difference between exact and approximate data should be used to define the percentage of error.

A specific file called ExactFeessBT.txt must include the values of Exact Fees before tax, which represent the exact fees before tax for each apartment based on the calculation of electric consumption and of each KW and the price of KW for category of consumption.