5.8. The factors that influence the breaking strength of a synthetic fiber are being studied. Four production machines and three operators are chosen and a factorial experiment is run using fiber from the same production batch. The results are as follows: Machine Operator 2 3 109 110 108 110 110 115 109 108 2 110 110 111 114 112 111 109 112 116 112 114 120 114 115 119 117 (a) Analyze the data and draw conclusions. Use a = 0.05. (b) Prepare appropriate residual plots and comment on the model's adequacy