Flag it briefly if the discrepancy could affect your interpretation, then keep moving.

Percentages may not sum to exactly 100% because of rounding, omitted categories or an 'other' segment.

If the gap is small and not decision-relevant, note the likely explanation and proceed. If your calculation depends on it, clarify.

The key is proportionality. Do not let a minor chart inconsistency consume time unless it changes the answer. For more on checking what an exhibit does and does not support, see the case interview data-analysis guide.

I lost a full minute on this once and it turned out to be rounding.