Answers:
Definite estimate is also termed as bottom-up estimate.
The accuracy of this estimate is much more as compared to the accuracy of the
above two estimates. However, the time required to prepare such type of
estimate is relatively more. In order to prepare a definite estimate, the
project manager must take the help of work breakdown structure (WBS). A project
manager requires a WBS for preparing a definite estimate because a project
manager needs to account for the cost of each and every deliverable.