Data Interpretation — IBPS Clerk / SBI Clerk
Clerk-level Data Interpretation is deliberately simpler than the PO-level version of the same topic: a single table, bar chart or line chart carries every question in a set, without the caselets, missing-value puzzles or embedded data-sufficiency questions that appear at PO level. The arithmetic itself — percentages, ratios, averages, differences — is identical to the Arithmetic Word Problems chapter; the only added skill is reading the chart accurately before calculating.
1. Reading the chart correctly, before calculating anything
Every DI set's entire difficulty sits in accurate reading — scan the chart once for its labels, units and scale before answering any individual question, since a single misread value produces a confidently wrong answer regardless of correct arithmetic afterward. A bar chart's y-axis scale matters as much as the bar heights themselves — a chart scaled in "hundreds" changes every answer by a factor of 100 if misread as raw units.
2. Total, average and share of total
Finding a chart's total is direct summation; the average is that total divided by the number of categories; a category's "share of total" is its own value divided by the total, expressed as a percentage. These three calculations recur in nearly every clerk-level DI set and are the fastest points available once the chart is read correctly.
3. Difference and ratio between two categories
A "difference" question subtracts one category's value from another directly; a "ratio" question expresses the same two values as a simplified ratio rather than a subtracted difference — reading which is actually being asked prevents answering the wrong calculation. Both questions use the exact chart values without any further estimation, once those values are correctly read.
4. Comparing one category against the average of the rest
A frequent clerk-level DI question asks how one category compares to the AVERAGE of the remaining categories, not the overall average including itself — this distinction changes the divisor and is a common misreading trap. Excluding the category in question from both the sum and the count before computing the average of "the rest" is what the question is actually asking for.
5. Percentage change across a line chart
A line chart's percentage-change question uses the same formula as any percentage increase — (new value minus old value), divided by the OLD value, times 100 — applied to two specific points read directly off the chart. As with any percentage-change question, the correct base is always the EARLIER value, never the later one.
Worked Examples
A bank's five branches report the following number of active savings accounts.
| Branch | A | B | C | D | E |
|---|---|---|---|---|---|
| Accounts | 420 | 580 | 350 | 650 | 500 |
Example 1. Find the total number of accounts across all five branches, and the average per branch.
Total . Average .
Answer: Total = 2,500, Average = 500.
Example 2. What percentage of the total accounts does Branch D hold?
.
Answer: 26%.
Example 3. Find the difference in accounts between Branch B and Branch C.
.
Answer: 230.
Example 4. How does Branch D's account count compare to the AVERAGE of the other four branches (A, B, C, E)?
Sum of the other four: . Their average: . Branch D (650) exceeds this average by accounts.
Answer: Branch D exceeds the average of the other four branches by 187.5 accounts.
A company's annual revenue (₹ lakh) over five years is shown below.
| Year | 2019 | 2020 | 2021 | 2022 | 2023 |
|---|---|---|---|---|---|
| Revenue | 180 | 200 | 240 | 210 | 270 |
Example 5. What percentage of the 5-year total revenue does 2021 represent?
Total . .
Answer: approximately 21.8%.
Example 6. Find the percentage change in revenue from 2022 to 2023.
.
Answer: approximately 28.6% increase.
Summary
Clerk-level DI stays to a single chart per set, with no caselets or missing-value layers — the entire difficulty is reading the chart's labels, units and scale correctly before calculating anything.
Total (summation), average (total ÷ count) and share of total (category ÷ total × 100) are the three most frequent calculations. Reading whether a question asks for a difference (subtraction) or a ratio (simplified proportion) determines which calculation is actually needed.
A question comparing one category to "the average of the rest" excludes that category from both the sum and the count — a common misreading trap when rushed. Percentage change always uses the EARLIER value as the base, never the later one.
