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Cleaning and Validating Sales Data

EasySQL & Data Manipulation00:00
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Your question is Cleaning and Validating Sales Data. 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).

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Problem

Context

Clean data is necessary before building reports in tools such as Coca-Cola Consolidated Power BI dashboards or recurring SQL-based KPI reporting. Interviewers ask this to see whether you can move from raw records to trustworthy analysis.

Core question

Explain how you would clean and validate a dataset before using it for analysis. Your answer should cover how you identify missing values, duplicates, invalid formats, inconsistent categories, and out-of-range values, and how you confirm that the cleaned data is reliable enough for reporting.

Scope guidance

Keep your answer practical and analyst-focused. You should describe a clear process, mention common SQL checks you would run, and explain how you would document assumptions or escalate issues when the source data itself is wrong.