IT projects are particularly challenging as we are frequently asked for cost and time estimates before we do the Requirements Phase. (For example, if we subcontract out a task, we sometimes are required to provide some sort of cost ceiling in the request for proposals.) Write approximately 150 words on how we, as IT professionals, can attempt to estimate time and cost when we don't know the requirements yet. (This is a real issue that many of you have faced. Feel free to provide examples, etc.)