Tag
Excel
2articles
November 2026
2 articles on this page
Data & analytics11 min readSimple regression in Excel without fooling yourself
For managers with an Excel sheet of ad spend and revenue who are about to report what one more million of advertising adds. Which function gives which number, how to read R² and the standard error, and three traps that keep a high R² wrong: a curve, one distant point, a slope that is not a cause.
- Data & analytics10 min read
Seasonal sales forecasting in Excel, scored with MAPE
For shop owners and buyers whose monthly sales swing with the seasons while the yearly total climbs. Five steps in Excel on an invented dataset, and a check on when they fail to beat a much simpler forecast.