SAS Statistical Business Analysis Using SAS 9: Regression and Modeling — Question 5

After performing an ANOVA test, an analyst has determined that a significant effect exists due to income. The analyst wants to compare each Income to all others and wants to control for experimentwise error.
Which GLM procedure statement would provide the most appropriate output?

Answer options

• A. lsmeans Income / pdiff=control adjust=dunnett;
• B. lsmeans Income / pdiff=control adjust=t;
• C. lsmeans Income / pdiff=all adjust=tukey;
• D. lsmeans Income / pdiff=all adjust=t;

Correct answer: A

Explanation

The correct answer is A because the Dunnett adjustment is specifically designed for comparing multiple treatment groups against a control, thereby controlling for experimentwise error. The other options either do not utilize the correct adjustment method for comparing against a control group (B) or use adjustments (C and D) that are not suitable for this specific scenario.