Final answer:
To add values from cell C4 across the 'Jan', 'Feb', and 'Mar' sheets in a Microsoft Excel workbook, use a formula with external cell references. This can be achieved using the SUM function with 3-D references if the sheets are adjacent, or by individually adding each sheet's cell value if they are not.
Step-by-step explanation:
The question involves creating a formula in a spreadsheet, specifically Microsoft Excel, which requires using external cell references to add values from the same cell across multiple sheets in a workbook. To achieve this in cell C4 of the PB Q1 workbook, you would use the following formula:
=SUM(Jan:Mar!C4)
This formula assumes that your sheets named 'Jan', 'Feb', and 'Mar' in the PB Jan_to_March workbook are adjacent. If the sheets were not sequentially named or placed, you would individually reference each sheet:
=Jan!C4 + Feb!C4 + Mar!C4
This formula adds the value of cell C4 from each of the three sheets together. This function utilizes 3-D references in Excel to sum across different sheets, a powerful tool for consolidating data in complex workbooks.