Question: A process for the manufacture of penicillin was studied. There were five variants of the basic process being studied, denoted by A, B, C, D and E. It was known that an important raw material, corn liquor, was quite variable. So each treatment was used with each different blend of corn steep liquor. (remember the interaction)
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Blend of Corn Liquor
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Treatment
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1
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2
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3
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4
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A
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89
|
88
|
97
|
94
|
|
B
|
84
|
77
|
92
|
79
|
|
C
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81
|
87
|
87
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85
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|
D
|
87
|
92
|
89
|
84
|
|
E
|
79
|
81
|
80
|
80
|
a. Analyze the data and do any plots you think are useful to test the adequacy of the model.
b. Find the 99% confidence interval for the difference between treatments A and C. Be sure to clearly state your conclusions (need lsmeans/pdiff=... cl).
c. Explain how the degrees of freedom of the error is calculated.