Data Interpretation
About 6 min · Quantitative Ability · English
Time worked out from the lesson's 393 words at 150 words a minute, plus a minute for each question.
Data Interpretation (DI) is part of HSSC CET's Quantitative Ability paper. It tests your ability to read, analyse and extract meaningful information from data presented in tables, bar graphs, pie charts and line graphs. Unlike pure arithmetic, DI requires you to first understand what the data represents, then apply basic calculations like percentages, ratios, averages and differences.
Key ideas
- Table Reading: Rows represent one variable (e.g., years), columns represent another (e.g., products or regions). Locate the intersection for your required value.
- Bar Graph Interpretation: Height of each bar shows the value. Grouped bars compare multiple categories; stacked bars show composition of a total.
- Pie Chart Logic: Each slice represents a percentage or proportion of the whole (360° = 100%). To find the actual value: (degree/360) × total or (percentage/100) × total.
- Line Graph Trends: Points connected by lines show change over time. Slope indicates rate of change — steeper slope means faster change.
- Percentage Change Formula: Change% = [(New Value − Old Value) / Old Value] × 100. Positive result means increase; negative means decrease.
Quick reference
- Percentage change = (Difference / Original) × 100 — always use OLD value as base
- Pie chart: 1% = 3.6°, so 25% = 90°, 50% = 180°
- For approximation: round to nearest 5 or 10, calculate, then adjust
- In tables: row-column intersection gives the required data point
- Line graph slope: steep upward = rapid increase; flat = stable; downward = decrease
Check yourself: 3 questions
1. The following table shows the number of students enrolled in five different schools in a city: School | Boys | Girls -------|------|------ A | 240 | 180 B | 320 | 280 C | 200 | 220 D | 360 | 340 E | 280 | 260 What is the total number of students enrolled in School D?
2. A bar graph shows the production of rice (in thousand tonnes) in a state over five years: Year 2019: 150 Year 2020: 180 Year 2021: 200 Year 2022: 170 Year 2023: 220 What is the average production of rice (in thousand tonnes) over these five years?
3. A pie chart shows the distribution of a family's monthly expenditure of Rs 48,000 across different categories: Food: 30% Rent: 25% Education: 20% Transport: 15% Miscellaneous: 10% How much more does the family spend on Food than on Transport?
This lesson is cut from the topic's note, not rewritten. Fact-checked on 18 Oct 2026: an AI-assisted check of this note against cited sources; the errors it found were corrected that day. Some errors may remain. The questions are from Shishya's validated question bank.
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