New PMP Question & Answers with explanation

Close Project or Phase is the process of completing and concluding all activities across all process groups to officially close the project. Which of the following activities is not performed during this process?
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Changes in projects are inevitable. Therefore, project managers must develop or use a system to manage and control changes. There are four types of changes that need to be controlled in a project: Project changes, deliverable changes, process changes, and baseline changes. The impact of each of these changes must be evaluated, and approved or rejected changes must be communicated to all stakeholders, as and when required. Which of the following helps control these changes?
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You have managed a federal highway construction project, which is intended to improve transportation between north and south regions of the country. In the execution phase, you received many complaints from stakeholders, including the highway transportation agency. At least half these complaints were regarding the quality of the micro texture of the road, and the nonconformance to the quality levels incorporated in the project quality management plan. So far, you have successfully fixed all the reported issues, but you are concerned by this recurrent event. What should you do to avoid future similar issues?
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There is a heavy demand for new houses in your city's expensive neighborhood. RECON, a construction company, has employed you as a project manager to assess the benefit of building new energy-efficient houses in that neighborhood, even though it takes more expensive technology to build such houses. You have started gathering data to perform a detailed payback analysis to submit a report to your management. Since the full financial impact of building energy-efficient houses is difficult to estimate, you would like to prepare a rough costbenefit analysis and include it with the report. Which of the following describes the effort you are undertaking in this scenario?
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You have presented a unique and verifiable product to your customers for their approval. Approval of this product may allow you to move on to your next phase. This unique and verifiable product is also known as:
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