In many consulting cases, especially data-heavy ones, you’ll be asked to interpret charts, spot trends, and extract insights from tables. This is a test of both your analytical sharpness and your ability to draw business conclusions under time pressure.
This article walks through common chart types, weighted average logic, and includes mini drills to sharpen your skills.
1. Types of Visuals You’ll Encounter
- Line charts: Used to show trends over time (e.g., revenue by quarter)
- Bar charts: Compare categories (e.g., sales by region or product)
- Stacked bar charts: Show breakdowns within totals (e.g., cost components)
- Tables: Often contain multiple variables like price, volume, and growth
2. Key Skills to Demonstrate
- Speed: Scan visuals quickly to spot the headline insight
- Accuracy: Avoid false assumptions—read labels and units
- Business logic: Go beyond the numbers: why is this happening?
3. Weighted Average in Tables
Sometimes, you’ll need to calculate an average across different categories with varying weights.
“A company sells Product A (60% of sales, margin 20%) and Product B (40% of sales, margin 40%). What’s the weighted average margin?”
Answer: (0.6 × 20%) + (0.4 × 40%) = 28%
This comes up when comparing performance across markets, customers, or product lines.
4. Typical Case Prompt
“Compare the two bar charts below: what’s driving the profitability gap between Market X and Market Y?”
Start by identifying differences in:
- Revenue growth or volume
- Cost structure (fixed vs variable)
- Customer mix or pricing
Use business intuition to explain differences—not just describe them.
5. Mini Drill #1 – Trend Identification
You see a line chart of monthly subscribers:
- Jan: 1.2M → Feb: 1.4M → Mar: 1.6M → Apr: 1.7M → May: 1.6M
“What’s your interpretation?”
Sample answer: Steady growth from Jan to Apr, but a dip in May may signal seasonality or churn. Worth investigating retention issues.
6. Mini Drill #2 – Table Comparison
Revenue table by region (in $M):
- North: 100 (20% growth)
- South: 80 (10% growth)
- East: 50 (5% decline)
- West: 90 (15% growth)
“Where should the client focus their sales investments?”
Sample answer: North and West are both large and fast-growing—doubling down here may yield better ROI than trying to fix the declining East region.
7. Final Tips
- Always articulate the business implication, not just the numbers
- Use estimates when precise data isn’t available
- If asked to calculate something, walk the interviewer through your logic
Great candidates don’t just read charts—they turn insights into smart decisions.