A psychologist operating a group home for delinquent adolescents needs to show that it is successful at reducing delinquency. He samples nine adolescents living in their parents’ home whom the police...

A psychologist operating a group home for delinquent adolescents needs to show that it is successful at reducing delinquency. He samples nine adolescents living in their parents’ home whom the police have identified as having problems, nine similar adolescents living in foster homes, and nine adolescents living in the group home. As an indicator variable, he uses truancy (number of days truant in the past semester), which is readily obtained from school records. On the basis of the following data, draw the appropriate conclusions.

Natural Home: 15 18 19 14 5 8 12 13 7

Foster Home: 16 14 20 22 19 5 17 18 12

Group Home: 10 13 14 11 7 3 4 18 2