Analyze a spreadsheet with AI: formulas, errors, and a verifiable result

Ask one question about the table

Start AI work in Excel with a question whose answer can be checked: ‘What is revenue from three orders after discounts?’ This is better than ‘analyze the business’. The latter leaves unclear which data was used, what success means, and where the recommendation came from. The first question requires only the source rows, each row’s formula, and the total.

We will examine a fictional stationery store. Every product, quantity, and price below is invented for learning. We did not run Copilot or upload the workbook to another service. This provides instructions to repeat yourself and reference answers calculated manually. Analyzing a real company requires its data, metric definitions, and separate verification.

Create a small workbook with clear units

For online AI spreadsheet analysis, start with educational rows you can paste as text into an available assistant; check returned formulas in the workbook itself. Whole-file work requires separate checks of supported formats and available features. This provides an Excel workflow rather than a promise that any website will process your table. Keep five columns: A — product, B — quantity, C — unit price, D — discount, E — revenue. Headers are in row one. Inputs occupy rows two through four, with column E initially empty. Enter the discount as a percentage number, such as 10%, rather than the text ‘ten percent’. Put the total separately from source rows.

The metric here is simple: quantity multiplied by price and the proportion remaining after the discount. We exclude delivery, returns, cost of goods, and taxes. The column is therefore called revenue after discount, rather than profit. Confusing these concepts can produce a mathematically correct number and a wrong conclusion about the store’s result.

Check the chosen tool’s current capabilities

Current Microsoft help describes Copilot assistance with formulas, calculated columns, totals, and explanations of existing expressions. AI-generated content must be checked. Do not use old instructions featuring the COPILOT cell function: Microsoft states that it became unavailable on September 14, 2026; use through the Copilot pane is separate.

Make sure your Excel version offers the necessary tools and lets you select the correct range. Cost, access rights, and your account’s particular feature have not been checked by this exercise. If the assistant is unavailable, enter the expressions below manually. A verifiable calculation should not depend on successfully opening an AI button.

A complete assistant assignment

Provide structure and data together: ‘In an educational workbook, A1:E4 has columns for product, quantity in units, unit price in rubles, percentage discount, and revenue after discount. Rows 2–4: Notebook, 3, 400, 10%; Pen, 10, 80, 0%; Folder, 4, 150, 5%. Column E is empty. Propose a formula for E2 and a way to extend it to E3:E4. Explain units and each operation. Calculate expected values and the total for these three rows. Do not include the header or total row as source sales. Do not rename revenue as profit. Do not invent returns, taxes, delivery, or cost of goods. Show which empty or text values prevent calculation; do not replace them with zero without a rule. First propose a solution, then provide a checklist. Do not change other sheets or claim to have checked the workbook if you see only its description.’

If the tool accesses the workbook itself, explicitly name the sheet and range. This small example is sufficient for a text assistant: you need not send a file containing real customers to determine a formula. Different discounts are included deliberately, making copying errors more visible than in three identical rows.

Reproduce the formulas manually first

For E2, the expression is =B2*C2*(1-D2). With 10%, D2 contains the fraction 0.1: 3 × 400 × 0.9 = 1080. For E3, references move to row three, producing 10 × 80 × 1 = 800. For E4, 4 × 150 × 0.95 = 570. The total E2+E3+E4 is 2450 rubles.

Check an independent route too. Before discounts, the sum is 1200 + 800 + 600 = 2600. Discounts total 120 + 0 + 30 = 150. Thus 2600 − 150 = 2450. Matching totals confirm the arithmetic of this educational example but do not prove other rows correct. If the model gives only a number without expressions and a range, ask it to reveal the calculation.

Check what happens with input errors

Apply checks to a copy of the file, one at a time. Record the changed cell, expected response, and actual result of your attempt. The table above is a test plan rather than a history of completed service testing. A missing price may appropriately stop calculation with a message; silently reconstructing the price from a neighboring row is unacceptable without an agreed rule.

Separate calculation from an attractive chart

After checking rows, request a revenue-by-product visualization. In our example, notebooks produce 1080 rubles, pens 800, and folders 570. Label the metric and units on the chart. Column order does not change the data, but incorrectly labeling it ‘profit’ changes interpretation. Do not ask the model to explain differences when it has only quantity, price, and discount.

Folders may have sold less often, had lower demand, or been part of another promotion; our table does not say. An acceptable conclusion describes observed numbers. A causal hypothesis must remain separate and list the data needed. A visualization helps show the result but does not itself add facts about the audience.

Save a reproducible result

Before finishing, retain the three source rows, calculated expressions, total, and rules for invalid values. Label units and metric limitations. Another person should be able to open the workbook, read the formula, and obtain the same result without access to the model conversation. Move important conversational conditions into a comment or sheet description.

For a large real table, start with a small sample including ordinary rows, a missing value, a return, and an unusual discount. Do not apply our simple metric where discounts are amounts and the price already includes some costs. Define column meanings first, then the formula. A corrected AI answer does not remove the need to recheck previously correct cases.

The exercise’s outcome is a checked table, rather than a promise that AI improved sales. In calculator development you check the program and input; in Excel, also sheet structure and range coverage. A saved reference example lets you repeat the check after the next data or assistant change.

Sources

• Microsoft: formulas and data analysis with Copilot in Excel
• Microsoft: retirement of the COPILOT function

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