Pivot Tables can help make your worksheets more manageable by summarizing data and allowing you to manipulate it in different ways. Make sure you review the video and all 6 pages related to Pivot Tables.
Excel includes many powerful tools to perform complex mathematical calculations, including what-if analysis. This feature can help you experiment and answer questions with your data, even when the data is incomplete. Review the video and all 4 pages instructing you on What If Analysis.