=+14.27 ● ▼ The article “The Undrained Strength of Some Thawed Permafrost Soils” (Canadian Geotechnical Journal [1979]: 420–427) contained the accompanying data

(see page 658) on y 5 shear strength of sandy soil (kPa), x1 5 depth (m), and x2 5 water content (%). The predicted values and residuals were computed using the estimated regression equation where , , and .