In Myers, Montgomery, and Anderson-Cook (2009), a data set is discussed in which a 23Â factorial is used by an engineer to study 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 duplicates are run at each design point with the order of the runs being random. The data are presented here.
A
B
C
Life
(1)
−
22,31
+
32,43
35,34
Ab
35,47
44,45
Ac
40,37
Bc
60,50
Abc
39,41
(a) Calculate all seven effects. Which appear, based on their magnitude, to be important?
(b) Do an analysis of variance and observe P-values.
(c) Do your results in (a) and (b) agree?
(d) The engineer felt confident that cutting speed and cutting angle should interact. If this interaction is significant, draw an interaction plot and discuss the engineering meaning of the interaction.
Already registered? Login
Not Account? Sign up
Enter your email address to reset your password
Back to Login? Click here