3. Use SAS ADX to create a quarter fraction 25????2 design.

(a) Examime the Confounding rules used by SAS ADX to create the design.

(b) Modify the SAS code for exercise 1 to create the same design.

(c) Determine the dening relation.

(d) Verify that the alias structure in SAS ADX (for this design) can be obtained from the dening relation you found in (c).

(e) Suppose that after analysis of data from this experiment that two main eects A and D appear to be signicant. Because of the confounding between main eects and two-factor interactions, interpreting the results to mean that these two main eects are the only signicant eects could be misleading. Using the eect heredity principle, suggest two alternate plausible models that could explain the data.

(f) List the experiments in a foldover fraction that you could use to augment the original eight experiments in order to remove the aliasing between main eects and two-factor interactions.