In Excel, there are two ways of calculating the weighted average with percentages: using the SUM function and using the SUMPRODUCT function. Let us have a look at these 2 methods in detail.

Calculate Z-scores for WorldCom using annual 10-K financial reports for years ending Dec. 31, 1999, 2000, and 2001. 4 5 6 You'll find that WorldCom's Z-score suffered a sharp fall.