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Level 2
· ◆◆ · ~12 min
Ordinary Least Squares
Ordinary Least Squares
"How the line is actually chosen: minimize the squared misses, and out pop two formulas you already half-know from statistics."
fitted values and residualssum of squared residuals (SSR)the least-squares criterionslope formula β̂₁ = Σ(xᵢ−x̄)(yᵢ−ȳ)/Σ(xᵢ−x̄)²intercept β̂₀ = ȳ − β̂₁x̄
A short lesson, then a quiz. ❤️×3 — a wrong answer costs a heart; finish with at least one left and the level is yours. Lose all three and you'll have to try again. Replay any time — XP and cleared levels are never lost.