10. (5) What are the differences between a construction manager's budget estimate during the preconstruction phase and a contractor's detailed lump sum construction bid estimate at the start of the construction phase? Which one is more accurate and why? 11. (3) What is escalation and why is it difficult to predict? project? When would more iterations be appropriate? When would less iterations be appropriate? 12. (5) How many design development and cost benefit iterations occur on a typical