Interactive model · regression
📈 Regression Lab: What Really Drives the Number?
Four real business datasets. Pick one and a predictor, and watch the least-squares line rotate into place from a flat guess. Slide the prediction marker to forecast, then check which predictors survive a significance test.
Least squares fitted in your browser; coefficients, standard errors and p-values match Excel's Data Analysis → Regression output.
🚚 Is the effect real? Confidence intervals for truck maintenance
Maintenance cost modelled on miles driven and truck age (n = 23, R² = 0.951). If a 95% interval includes zero, we can't rule out "no effect".