In cell C4 of the PB workbook, enter a formula, using external cell references, that add together the values from C4 in all sheets of the PB Jan_to_March
To add together the values from cell C4 in all sheets of the workbook "PB Jan_to_March", you can use the following formula in cell C4:
=SUM('PB Jan_to_March'!C4:C4)