The following PMP® exam sample question is taken from http://www.free-pm-exam-questions.com - The answer is at the very bottom:


------------------------------
PMBOK Section: Estimate Costs                              

Process Group:     Planning Process Group                                        

Question Type:     Calculation                                   

Knowledge Area: Cost Management                                    

Difficulty Level:   Easy                                                                                                         

Question: You are managing an amusement park development project. You have received the following estimates for site excavation and area development activity that is critical to the success of your project. The most likely estimate is $100,000, the optimistic estimate is $90,000, and the pessimistic estimate is $120,000. What is the expected activity cost?                                                                                                                      

            A.        $101666                                                                                                         

            B.        $100000                                                                                                         

            C.        $120000                                                                                                         

            D.        $90000                                                                                                           

Hint:    Use the PERT formula.                                                                      

Reference: PMBOK4 - pg:173                                                                                                                                  

                                                                                                                                                 -----------------------------


All our free questions are updated to the latest PMBOK® Guide standard. Sign up here to receive the questions via email. We are a PMI Registered Education Provider.

Until next time,
Cornelius Fichtner, PMP
The Project Management PrepCast™ - http://www.project-management-prepcast.com
The Project Management Podcast™ - http://www.project-management-podcast.com

Explanation:   PMBOK recommends the use of PERT in estimating durations and costs. The PERT estimation formula is (Optimistic + 4xMost Likely + Pessimistic) / 6. For the given data, this results in 101,666.66. Hence choice A is the correct answer to the question.