Excel Statistical Data Cleaning

I have a completed statistical analysis stored in a single Excel workbook, but the underlying dataset still contains issues that compromise the findings. What I need right now is a focused round of data cleaning: spotting and fixing entry errors, removing duplicates, handling out-of-range or missing values, and making sure every variable is coded consistently so the final numbers are trustworthy and ready for deeper modelling.

You will start from the original spreadsheet I supply, work directly in Excel (no format conversions), and return:
• the cleaned file with every change tracked or highlighted, and
• a short changelog explaining what was corrected and why.

If you notice minor calculation glitches while cleaning, feel free to flag them—future error-correction or visualisation work may follow, but this brief is strictly about delivering a pristine dataset.