A study carried out to investigate the relationship between a response variable relating to pressure drops in a screen-plate bubble column and the predictors fluid velocity, viscosity, and mesh size resulted in the accompanying data (“A Correlation of TwoPhase Pressure Drops in Screen-Plate Bubble Column,”

Canad. J. of Chem. Engr., 1993: 460–463). The standardized residuals and hii values resulted from the model with just x1, x2, and x3 as predictors. Are there any unusual observations?