Regression lines
Correlation, regression and applied statistics · Mathematics
Study notes
Q: x̄ = 10, ȳ = 20, s_x = 2, s_y = 5, r = 0.8. Find the regression line of y on x. b = r(s_y/s_x) = 0.8 × (5/2) = 0.8 × 2.5 = 2. a = ȳ - bx̄ = 20 - 2×10 = 0. Line: y = 2x. Predict: x = 12 → y = 24!