For Exercises 17–20, use level of significance to do the following for the indicated data:

  1. Test for interaction. Confirm that the result agrees with the interaction plot you constructed.
  2. If appropriate, test for the Factor A effect.
  3. If appropriate, test for the Factor B effect.

Question 12.135

19. Data in Exercise 15

12.4.19

(a) : There is no interaction between carrier (Factor A) and type (Factor B). : There is interaction between carrier (Factor A) and type (Factor B). Reject if the . The , which is not ; therefore we do not reject . There is insufficient evidence of interaction between carrier (Factor A) and type (Factor B) at level of significance . This result agrees with the interaction plot in Exercise 15.(b) : There is no carrier (Factor A) effect. That is, the population means do not differ by carrier. : There is a carrier (Factor A) effect. That is, the population means do differ by carrier. Reject if the . The , which is ; therefore we reject . There is evidence for a carrier (Factor A) effect. In other words, there is evidence at level of significance that the population means do differ by carrier. (c) : There is no type (Factor B) effect. That is, the population means do not differ by type. : There is a type (Factor B) effect. That is, the population means do differ by type. Reject if the . The , which is ; therefore we reject . There is evidence for a type (Factor B) effect. In other words, there is evidence at level of significance that the population means do differ by type.