Your question is Correcting a Critical Data Anomaly. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Tell me about a time you found an anomaly in a large, messy dataset that could have affected a financial decision or report. How did you investigate it, correct it, and make sure the issue did not happen again?