Sales Trend Analysis in Excel

I have a raw dump of sales data that I want turned into a clear, insight-driven trend analysis inside Excel. Your job will be to clean the file, structure it for analysis, and then surface month-over-month and year-over-year patterns using pivot tables, dynamic charts, and any built-in statistical functions that help tell the story at a glance.

At a minimum I expect:
• A well-structured, self-updating workbook with labeled sheets for raw data, cleaned data, and final dashboards
• Interactive visuals (line or column charts, slicers, conditional formatting) that highlight key sales trends, peaks, and dips
• A short written summary within the workbook explaining the main findings and formulas used

If you prefer Power Query or Power Pivot for the ETL step, feel free—just keep everything contained in the .xlsx file so it runs on a standard desktop install of Excel 2019 or later. Accuracy and clarity matter more to me than fancy design; by the end I want to open the file, change or append new sales rows, hit refresh, and immediately see updated trend insights.