An experiment was conducted to determine the factors in the bag-sealing equipment that might be affecting the ease of opening the bags without tearing the inner liner of the bag. Data were collected on

19

bags and the plate gap on the bag-sealing equipment was used to predict the tear rating of a bag. The data are modeled by

Yi=0.7505+0.4970Xi,

where

Xi

is the plate gap and

Yi

is the tear rating. Perform a residual analysis for these data. Based on these results, evaluate whether the assumptions of regression have been seriously violated.