Question

13. For each of the following studies, decide whether you can reject the null hypoth- esis that the groups come from identical populations. Use the 05 level. (a) Group 1 Group 2 Group 3 10 12 (b) Group 1 Group 2 Group3 10 10 12 10 14 (c) Group 1 Group 2 Group 3 10 18 (d) Group 1 Group 2 Group 3 10 12 14 2.5

Answer 1

a)

ANOVA Table... Source of Variation Sum of Squares d.f. Variance Between Groups: 40.0000 Within Groups: 60.0000 20.0000 4.0000 2 12 14 0.0467 5.0000 Total: 100.0000

p-value = 0.0467 < 0.05

hence we reject the null hypothesis

b)

ANOVA Table.. d.f Source of Variation Sum of Squares Variance 160.0000 32.0000 Between Groups: 320.0000 Within Groups: 135.0000 Total: 455.0000 2 27 29 0.0000 5.0000

p-value = 0.0000 < 0.05

hence we reject the null hypothesis

c)

ANOVA Table.. Source of Variation Sum of Squares d.f Variance 16.0000 Between Groups: 160.0000 Within Groups: 60.0000 Total: 220.0000 2 80.0000 0.0004 5.0000

p-value = 0.0004 < 0.05

hence we reject the null hypothesis

d)

ANOVA Table... Source of Variation Sum of Squares d.f. Variance 80.0000 Between Groups: 160.0000 2 32.0000 0.0000 Within Groups: 30.0000 2.5000 12 Total: 190.0000

p-value = 0.0000 < 0.05

hence we reject the null hypothesis