| name | Weighted Mean Calculation with SUMPRODUCT |
| description | Calculate a weighted average using SUMPRODUCT when weights and values have a one-to-one correspondence. Use this for computing aggregate statistics where different entities have different importance (weights). |
When to Use
- You have values and corresponding weights in aligned rows/columns
- You need a single weighted average metric
- Weights and values must be in the same column/row order
Formula Structure
=ROUND(SUMPRODUCT(values_range, weights_range) / SUM(weights_range), 1)
Where:
values_range: The percentages to be weighted (already in percentage format, e.g., 12.3)weights_range: The weights (e.g., GDP values or population)- Divide by
SUM(weights_range) to normalize
- Multiply by 100 is NOT needed if values are already displayed as percentages
ROUND(..., 1) rounds to one decimal place
Step-by-Step for GCC Net Exports Weighted Mean
- Identify your values: Net exports as % of GDP (from Step 2, cells H35:L40)
- Identify your weights: GDP values (from Step 1 lookup, row 26 — cells H26:L26)
- Verify alignment: Each column in H35:L40 corresponds to the same column in H26:L26
- Write the formula:
=ROUND(SUMPRODUCT(H35:L40, H26:L26) / SUM(H26:L26), 1)
Critical:
- Do NOT multiply by 100 in the SUMPRODUCT formula — the net export percentages are already multiplied by 100 from Step 2
- The final ROUND should happen only once, on the entire result
- Verify row numbers: H35:L40 (net exports %) and H26:L26 (GDP weights) must match your Step 1 and Step 2 placements
Common Mistakes to Avoid
- ✗ Multiplying by 100 twice (once in Step 2, again in SUMPRODUCT)
- ✗ Using different row ranges for values and weights (e.g., H35:L40 vs. H27:L27)
- ✗ Rounding intermediate calculations before the final result
- ✗ Forgetting to divide by SUM(weights_range) to normalize
