GMAT Focus Edition — Data Insights: Table Analysis · Graphics Interpretation · Multi-Source Reasoning · Two-Part Analysis
Home Course Data Insights Lesson 2
Data Insights Lesson 2 of 20

Data Insights:
Graphics Interpretation Mastery

Read the axis first. Identify chart type. Locate the data point. Fill the blank with the most precise answer available. Never skip the scale.

50 mins
🎯 DI 75 to 88
📚 Prereq: Lesson 1 (Table Analysis)
Note: Graphics Interpretation tests precise chart reading. Read the axis scale first, interpolate carefully, and distinguish between absolute values and percentages.
1

What Is Graphics Interpretation?

Graphics Interpretation (GI) presents a visual — a bar chart, line graph, scatter plot, or pie chart — with a passage and 2-3 statements to complete. You select from a dropdown to fill in each blank. The skill: extract precise data from imprecise-looking visuals.

Animated Bar Chart — Q3 Revenue by Division ($M)
$42M
Sales
$68M
Tech
$29M
HR
$55M
Ops
$37M
Mktg
Total revenue: $231M across 5 divisions
2

The Four Chart Types You'll See

Bar Chart

Compares categories. Bars = quantities. Read the y-axis scale carefully (starts at 0? truncated?).

Best for: comparing discrete categories at one point in time
Line Graph

Shows trends over time. The slope = rate of change. Crossing lines = same value at that point.

Best for: tracking change over time
Scatter Plot

Shows relationship between two variables. Cluster direction = correlation. Outliers = lone dots.

Best for: correlation, clustering, outlier detection
Pie Chart

Shows proportions of a whole. Sectors = percentages. Always sum to 100%.

Best for: part-to-whole relationships
3

Reading Charts Precisely

Critical: Read the Y-Axis Before Anything Else

Check: What are the units? Does the scale start at zero or is it truncated? What are the intervals? A bar that looks 3× taller may only represent a 20% difference on a truncated axis.

Interpolation Technique

When a bar or point doesn't land exactly on a grid line, interpolate:

If bar is 60% of the way between 40 and 50, its value ≈ 40 + 0.6×10 = 46.
4

Fill-in Strategy for GI Questions

GI 3-Step Strategy
Read the blank
What type of answer: a number, rank, comparison, or category?
Locate in chart
Find the specific data point, trend, or comparison needed
Select & move on
Don't overthink — pick the dropdown answer and proceed
5

10 Graphics Interpretation Traps

⚠ Y-axis truncation illusion

A bar chart with y-axis starting at 80 makes a 85 vs 90 difference look enormous. Always check the baseline.

⚠ Misreading grid lines

Between 40 and 50, each grid line might represent 2 units. Count carefully before interpolating.

⚠ Pie chart — total unknown

A pie chart shows percentages, not absolute values. Without the total, you can't find actual counts.

⚠ Two y-axes on one chart

Some bar+line combo charts use two different y-axes. Check which axis applies to which series.

⚠ Slope vs value

A steep slope means rapid change, not necessarily a large absolute value. Don't confuse rate with level.

⚠ Correlation ≠ causation

A scatter plot showing two variables moving together does NOT mean one causes the other.

⚠ "Approximately" answers

GI often asks for approximations. Don't waste time on exact arithmetic — choose the closest answer.

⚠ Legend confusion

Charts with multiple data series require careful legend-reading. Mixing up which line/bar is which is a common error.

⚠ Percent vs percentage points

Revenue grew from 20% to 25% — that's a 5 percentage-point increase, but a 25% relative increase. Different things.

⚠ Stacked bar chart components

In a stacked bar chart, to find the value of a segment, subtract the lower boundary from the upper boundary of that segment.

10 Practice Questions

Q1 of 10
GI~550

A bar chart shows quarterly revenue for 5 divisions. Tech division bar reaches $68M. The total of all bars is $231M. According to the chart, Tech's revenue as a percentage of total is approximately:

Explanation: About 29%. $68M / $231M ≈ 0.294 ≈ 29%. Always divide the specific value by the total to find percentage share.
Q2 of 10
GI~600

A line graph shows Company A's stock price from January to June: Jan $40, Feb $44, Mar $42, Apr $50, May $48, Jun $55. The statement says: "The largest month-over-month increase occurred in ___."

Explanation: March to April. Changes: Jan→Feb: +$4. Feb→Mar: -$2. Mar→Apr: +$8 ← largest increase. Apr→May: -$2. May→Jun: +$7. The biggest single-month jump is March to April (+$8).
Q3 of 10
GI~600

A pie chart shows market share: Company A 35%, Company B 28%, Company C 22%, Others 15%. Total market size is $800M. Company B's absolute revenue is approximately:

Explanation: $224M. $800M × 28% = $800M × 0.28 = $224M.
Q4 of 10
GI~600

A scatter plot shows Advertising Spend (x-axis) vs. Sales (y-axis) for 20 companies. The points cluster in an upward-sloping band from lower-left to upper-right. This pattern indicates:

Explanation: A positive correlation between advertising and sales. Points sloping from lower-left to upper-right indicate that as advertising spend increases, sales tend to increase — a positive correlation. This doesn't prove causation.
Q5 of 10
GI~700

A bar chart has a truncated y-axis starting at 200 (not 0). Bar A reaches 220, Bar B reaches 240. A student says "Bar B is twice as tall as Bar A, so B has twice the revenue." This reasoning is:

Explanation: Incorrect — B is visually 2× taller but only about 1.09× the actual revenue. On a truncated axis starting at 200, the visible bar lengths exaggerate differences. The actual ratio is 240/220 ≈ 1.09, not 2.0. Truncated y-axes systematically mislead visual comparisons.
Q6 of 10
GI~650

A stacked bar chart shows Q1 and Q2 totals for three product lines. In Q1: Product 1 = 30%, Product 2 = 45%, Product 3 = 25% of $100M. In Q2: the total grew to $120M with the same proportions. Product 2's absolute revenue INCREASE from Q1 to Q2 is:

Explanation: $9M. Q1 Product 2: 45% × $100M = $45M. Q2 Product 2: 45% × $120M = $54M. Increase = $54M − $45M = $9M.
Q7 of 10
GI~650

A line graph shows two companies' cumulative growth from Year 1 to Year 5. Company X starts at $50M and ends at $80M. Company Y starts at $20M and ends at $40M. Which company had a higher percentage growth?

Explanation: Company Y — 100% growth. Company X: ($80M−$50M)/$50M = 60% growth. Company Y: ($40M−$20M)/$20M = 100% growth. Absolute dollar growth is misleading — percentage growth is the correct comparison.
Q8 of 10
GI~700

A scatter plot has a line of best fit running through it. A specific data point sits well ABOVE the line of best fit. This means:

Explanation: The point has a higher value than predicted. Points above the line of best fit have actual y-values that exceed what the model would predict for their x-value. This doesn't mean it's an error — it's simply an over-performer relative to the trend.
Q9 of 10
GI~650

A dual-axis chart shows: bars (left axis) for monthly sales volume; a line (right axis) for average selling price. In March, the bar is at 500 units (left axis) and the line is at $120 (right axis). Total March revenue is:

Explanation: $60,000. Revenue = Units × Price = 500 × $120 = $60,000. On a dual-axis chart, always match each data series to its correct axis before calculating.
Q10 of 10
GI~600

A pie chart shows 5 categories. Category C has the largest slice at approximately 40%. The total sample is 250 respondents. If a statement says "Category C has at least 90 respondents," this statement is:

Explanation: True. 40% of 250 = 100 respondents. Since 100 ≥ 90, the statement "at least 90" is True. Note: even if the slice is only approximately 40% (say 38%), 38% × 250 = 95 > 90, still True.
Lesson Summary
Read the y-axis scale before anything

Truncated axes distort visual comparisons. Always check where the scale starts.

Interpolate between grid lines

Use proportional estimation: 60% of the way between 40 and 50 = 46.

Pie charts: need the total for absolute values

Percentages are relative. Multiply by the total to get absolute counts.

Scatter plots: direction = correlation sign

Up-right slope = positive correlation. Down-right = negative. No pattern = no correlation.