Check the number claim
Check the number claim
A draft analytics summary, mostly written by an AI assistant, contains this line: “Customer churn improved from 4.2% to 3.8% — a 12% reduction in churn.” The number is going into a board slide.
What is the right first move?
Hint
The raw numbers can be right while the percentage derived from them is wrong — check the derivation, not just the source.
Absolute change and relative change are two different figures: 4.2 → 3.8 is a 0.4-point move, which is a certain percentage of the starting value.
Why this is the answer
“4.2% to 3.8%” is an absolute drop of 0.4 percentage points; as a relative change it is 0.4 ÷ 4.2 ≈ 9.5% — not the claimed 12%. Nothing looks wrong: the format is right, the direction is right, and it is off by a quarter. Derived figures (rates, totals, growth) are where AI drafts fail most plausibly, so they get recomputed before they ship — especially the one destined for a board slide, where the number will be quoted without its context.