(a) Accurate estimation is crucial for effective planning and control and is related with time, information, experience of estimator, techniques used and funding. Discuss the three main types of Estimating Methodology.

(b) The project lifecycle denotes to a logical sequence of activities to accomplish the project's goals and objectives. Regardless of the scope or complexity, any project goes through a series of stages during its life. Elaborate those stages in a project life cycle.

(c) If project scope changes at several stages in the life cycle, discuss on the level of effort, level of influence and cost of changes in the project.