* According to the PMBOK Guide, 6th edition, section 6.4.2.6, the Monte Carlo method is a simulation technique that uses probability distributions and random sampling to compute possible outcomes of cost or schedule estimates.3
* The Monte Carlo method can produce different results each time it is run, depending on the input data and the random numbers generated.4
* Therefore, the project manager and the stakeholder may have used different input data, assumptions, or scenarios when applying the Monte Carlo method, resulting in different estimations for the budget.4
* The project manager and the stakeholder should compare and validate their estimations, and agree on a common baseline for the budget.
The references for this answer are:
1: PMP Exam Questions | 100% Free PMP Example Questions 2: PMP Practice Exam 1 | Free PMP Exam Questions 3: PMBOK Guide, 6th edition, Project Management Institute, 2017, pp. 200-201. 4: [Monte Carlo Simulation: What Is It and How Does It Work? - Palisade] : [Project Cost Management: The Ultimate Guide - ProjectManager.com]