申論題

9. A large chain of fast-food restaurants tested four different advertising programs to see if they differed in effectiveness. Four areas having similar economic and demographic conditions were selected. Area 1 was assigned program A； Area 2, Program B； Area 3, Program C； and Area 4 was
assigned Program D. The assignments of the programs were random. At the end of one month,four restaurant units were selected randomly from Area 1, four from Area 2, six from Area 3, and eight from Area 4. The gross sales (in thousands of dollars) during the last week of the advertising period are collected. Assuming that the data in the populations are distributed normally, are there statistically significant differences among the four advertising programs as measured by the gross sales? If you try to answer this question, please set:

(a) The Null Hypothesis, and the Alternative Hypothesis. 5%
You compute SST (Total Sum of Squares), SSG (Group Sum of Squares) and SSE (Error Sum of Squares), and determine DF (Degrees of Freedom) to test the hypothesis. The Level of Significance:
α = 0.05.