Penicillin Yields. In Statistics for Experimenters (New York, NY: John Wiley &Sons, Inc., 1978),G. Box, W. Hunter, and J. Hunter describe an experiment to determine the effect on yield of four...

Penicillin Yields. In Statistics for Experimenters (New York, NY: John Wiley &Sons, Inc., 1978),G. Box, W. Hunter, and J. Hunter describe an experiment to determine the effect on yield of four variants of a process for producing penicillin. A basic material in the production process, corn steep liquor, was known to be quite variable. Five blends of corn steep liquor were obtained, and each blend was divided into four equal parts. The four process variants were randomly assigned to the four parts in each blend. The penicillin yields are given in the following table.

Extracted text: Process Variant A B D 89 88 97 94 84 77 92 79 81 87 87 85 87 89 92 84 5 79 81 80 88 2. 3. 4. Blend