Regression Tests and Models

A verified 649-case regression coefficients guide covering raw slopes, standardized beta, confidence intervals, partial and part correlations, VIF, and Python, R, SPSS, and Excel evidence.

A verified 649-case regression confidence interval guide separating coefficient, mean-response, and individual prediction uncertainty with matched Python, R, and SPSS evidence.

A verified 649-row zero-inflated Poisson analysis with exact count and inflation formulas, zero calibration, model comparisons, diagnostics, and software files.

A verified 649-case guide to feasible WLS, Breusch-Pagan diagnostics, log variance modeling, stabilized inverse-variance weights and Python, R, SPSS and Excel outputs.

A verified left-censored Tobit analysis with 649 observations, exact likelihood formulas, latent coefficients, marginal effects, diagnostics, and contamination-safe media.

Understand stepwise regression with a verified both-direction AIC path, 12 candidate predictors, five selected terms, exact coefficients, diagnostics, charts, and reporting cautions.

A verified 649-case regression ANOVA table guide with exact sums of squares, degrees of freedom, mean squares, F test, diagnostics, and Python, R, SPSS, and Excel evidence.

A verified 649-case regression assumptions audit covering functional form, residual normality, variance, independence, VIF, influence, and matched Python, R, SPSS, and Excel evidence.

A verified 649-case guide to L2 regularization, leakage-safe scaling, cross-validated lambda selection, coefficient paths and separate Python, R, SPSS and Excel results.

A verified 649-case guide to the G3-on-G2 line, slope, intercept, correlation, ANOVA, confidence and prediction intervals, influence and software-specific outputs.