A researcher is interested in the effects of birth order (only child versus first born versus later born) on achievement in a group of middle school Right-handed and Left-handed children. The researcher believes that birth order has a differential effect on achievement in Right-handed and Left-handed children.Data were collected on a standardized test taken by all students (both Right-handed and Left-handed children) in the 8th grade (higher scores indicate greater achievement).The data are given below:

 

Birth Order Only    First     Later

 

1	8	15
Right-handed 2	9	16
3	10	17
4	11	27
Left-handed     5	12	28
6	13	29

 

Perform the appropriate analysis. Follow up any main effects with Scheffe’s follow-up tests.

Describe the findings fully, including an analysis of the interaction using Simple Effects follow-up tests.

Was the researcher's hypothesis supported?