A psychologist operating a group home for delinquent adolescents needs to show that the home is successful at reducing delinquency. He samples 10 adolescents living in their own homes who have been identified by the police as having problems, 10 similar adolescents living in foster homes, and 10 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 Foster Group Home Home Home 15 16 10 18 14 13 19 20 14 14 22 11 5 19 7 8 5 3 12 17 4 13 18 18 7 12 2