Excel Sales Forecast Dashboard

I need an Excel dashboard for linear regression analysis to predict future sales using existing Excel datasets.

Requirements:
- Dynamic tables, updated monthly
- Linear regression model for sales forecasting
- Auto-refresh charts/calculations with new data
- Clear insights presentation:
- Monthly sales trends (Bar and Line charts)
- Forecasted values (Separate forecast section)
- Key variance analysis (Actual vs Forecast)

Maintainable and well-documented formulas/data models for future updates are essential.

Ideal Skills and Experience:
- Advanced Excel proficiency
- Experience with linear regression and data modeling
- Strong data visualization skills