Consider the experiment described in Problem 6.1. Analyze this experiment assuming that each replicate represents a block of a single production shift.
Problem 6.1:
An engineer is interested in the effects of cutting speed (A), tool geometry (B), and cutting angle (C) on the life (in hours) of a machine tool. Two levels of each factor are chosen, and three replicates of a 23 factorial design are run. The results are as follows:
(a) Estimate the factor effects. Which effects appear to be large?
(b) Use the analysis of variance to confirm your conclusions for part (a).
(c) Write down a regression model for predicting tool life (in hours) based on the results of this experiment.
(d) Analyze the residuals. Are there any obvious problems?
(e) On the basis of an analysis of main effect and interaction plots, what coded factor levels of A, B, and C would you recommend using?