5. Copilot: Prompts and Checking the Answer

A good prompt for Copilot (or any other AI assistant) says what to calculate, from which data (table, columns), under which conditions (city, period), and in what form you want the answer (a formula, a number, a chart). Compare:

• weak: "calculate sales";
• strong: "In the table A1:C9, calculate the average deal for Austin only and the total sales for Boston. Give me the formulas, and take the tax rate from F7."

Suppose this answer comes back:

Average deal in Austin: =AVERAGE(C2:C9)
Boston revenue: $2,240
Boston revenue with tax: =2240*1.08

It contains three mistakes: the average is taken over all cities rather than Austin; the Boston total is incomplete (the AI skipped a row); and the tax rate is typed into the formula as a number even though it sits in a cell. An AI answer is a draft: check the condition in the formula, the range, and recalculate the key numbers with your own formulas.