Rework Problem 13.8 using the REML method.
Problem 13.8:
In Problem 5.8, suppose that there are only four machines of interest, but the operators were selected at random.
(a) What type of model is appropriate?
(b) Perform the analysis and estimate the model components using the ANOVA method.
Problem 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:
(a) Analyze the data and draw conclusions. Use α = 0.05.
(b) Prepare appropriate residual plots and comment on the model's adequacy.