The following data represent the means for each treatment condition in a two-factor experiment.Note that one mean is not given.What value for the missing mean would result in no A ´ B interaction? B1 B2

A1

20

30

A2

10

A)10
B)20
C)30
D)40

Question

The following data represent the means for each treatment condition in a two-factor experiment.Note that one mean is not given.What value for the missing mean would result in no A ´ B interaction? B1 B2
​
A1
​
20
​
30
​
A2
​
10
​
​
A)​10
B)​20
C)30
D)​40

Quizplus · Accepted Answer

To test for interaction, we look for differences in differences across the levels of the other factor. In other words, we compare the difference between B1 and B2 at each level of A. If there is no interaction, those differences should be the same. Given the means provided, the difference between B1 and B2 at A1 is 10 (20-30) and at A2 is unknown (since it is not given). To find the missing mean that would result in no interaction, we need to make sure that the difference between B1 and B2 is also 10 when A is A2. The only value that would satisfy this is 20 (30-10=20). Therefore, if A2 has a mean of 20, there would be no A x B interaction.

The Following Data Represent the Means for Each Treatment Condition