Repeat Problem 8-12 using 1 = -ABCD. Does use of the alternate fraction change your interpretation of the data?

Problem 8-12

Analyze the data in Problem 6-23 as if it came from a 2^4-1_IV design with 1 = ABCD. Project the design into a full factorial in the subset of the original four factors that appear to be significant.

Problem 6-23

In a process development study on yield, four factors were studied, each at two levels: time (A), concentration (B), pressure (C), and temperature (D). A single replicate of a 2⁴ design was run, and the resulting data are shown in the following table:

Actual Run Order Factor Levels Run Yield Number A B C D (lbs) Low (-) High (+) 1 5 12 A (h) 2.5 3 18 B (%) 14 18 C (psi) 60 D (C) 225 3 8 13 80 4 13 16 250 5 3 17 7 15 7 14 20 8 1 15 9 6. 10 10 11 25 11 2 13 12 15 + 24 13 4 19 14 16 21 15 10 17 16 12 23 + + + + + + + + + + + + +I + 1 + | + | +