Entain interview question

The task was to review a Power BI dashboard called "NCE Sales Performance Dashboard" against 8 acceptance criteria. I had to validate revenue calculations, check data quality, and log defects. I wrote SQL queries to verify the data, found that the DAX formula was mathematically incorrect — using SUM(quantity) * SUM(price) instead of row-by-row calculation — which caused revenue to be overstated by 120%. I also identified data quality issues like negative quantities, blank country codes, and orphaned product IDs.