If you’re preparing for the PL-300: Microsoft Power BI Data Analyst certification, understanding which visualization to use for different analytical scenarios is key. Let’s walk through a common practice assessment question and not only find the correct answer, but also explain why it’s the best choice.
Question:
You plan to create a report in Power BI Desktop.
You need to create a visualization to display a running total. The solution must meet the following requirements:
- The initial and the final value columns must start on the horizontal axis.
- The intermediate values must be floating columns.
Which type of visualization should you use?
Select only one answer.
- Combo
- Funnel
- Scatter
- Waterfall ✅
📝 Answer Explanation
The correct answer is Waterfall.
A Waterfall chart in Power BI is designed specifically for showing running totals and the impact of individual categories on a cumulative result.
🔎 Why Waterfall?
- Initial value is shown as a solid column.
- Intermediate values (positive or negative) appear as floating columns.
- Final total is displayed as the last solid column.
- Provides a clear, step-by-step breakdown of how you reach the end result.
❌ Why not the others?
- Combo chart → Good for comparing trends with multiple chart types (bar + line), but not designed for running totals.
- Funnel chart → Best for pipeline analysis (e.g., leads → opportunities → deals closed), not cumulative changes.
- Scatter chart → Plots relationships between two numeric variables, not sequential totals.
🎯 Real-World Use Cases
- Finance: Starting cash balance → revenue → expenses → ending balance.
- Sales: Starting quota → regional contributions → final achieved sales.
- Budgeting: Initial budget → adjustments → final actuals.
✅ Conclusion:
When your Power BI report needs to show how values accumulate step by step, with the starting and ending totals clearly highlighted, the Waterfall chart is the right visualization to use.
Learn more about What are Waterfall Charts in Power BI