/* SAS Example 9: Unbalanced 2-way ANOVA: Incorrect Analysis		 */

/* A company has conducted a consumer research project to ascertain
   customer service ratings from its customers. The customers were
   asked to rate the company on a scale from 1 to 7 on various
   quality characteristics. One question was the promptness of
   company response to a repair problem. The following data represent
   customer responses to this question. The customers were divided
   by geographic region and by age. Use analysis of variance to
   analyze the responses. Let alpha = .01.							 */

OPTIONS PS=52;
OPTIONS LS=78;
OPTIONS NODATE;
OPTIONS PAGENO=1;

DATA COMPANY;
	INPUT AGE $1-16 REGION $17-27 RATING;
	CARDS;
		21-35	Southeast	2.6666666667
		21-35	West		3
		21-35	Midwest		2.6666666667
		21-35	Northeast	2.5
		36-50	Southeast	5
		36-50	West		4.5
		36-50	Midwest		5.3333333333
		36-50	Northeast	5
		Over 50	Southeast	2.25
		Over 50	West		2.3333333333
		Over 50	Midwest		2.6666666667
		Over 50	Northeast	2
		;
RUN;

PROC PRINT DATA=COMPANY;
	TITLE 'Company Service Rating Means';
RUN;

PROC ANOVA;
	CLASS AGE REGION;
	MODEL RATING = AGE REGION AGE*REGION;
RUN;