Suppose you are interested in developing a counseling technique to reduce stress within marriages. You randomly select two samples of married individuals out of ten churches in the association. You provide Group 1 with group counseling and study materials. You provide Group 2 with individual counseling and study materials.

At the conclusion of the treatment period, you measure the level of marital stress in the group members. Here are the scores:

Group-1 Group-2 25 17 29 29 26 24 27 33 21 26 28 31 14 27 29 23 23 14 21 26 20 27 26 32 18 25 32 23 16 21 17 20 20 32 17 23 20 30 26 12 26 23 7 18 29 32 24 19