Fixed Costs and Variable Expenses in Business

How do they know they will need to 100,000,000 $ to start your business?
Did research on the rates for future expenses? Cost determined by dividing the fixed costs and variable expenses? How can know exactly how much will cost your business? Obviously, if you have done this exercise without great precision, then set the cost as the lowest cost and revenue as the turnover will be more up … but otherwise they should do in order to avoid unpleasant surprises, such as even if the new people who make a business and looking for credit. The banks know it, and that’s the reason I have a refusal on his application for funding. Their ability to repay is based on its ability to generate revenue and not pretty paper and pretty useless to look good analysis.