A new method of guided bone regeneration was evaluated in the Journal of Tissue Engineering (Vol. 3, 2012). The method involves attaching a titanium plate and silicon membrane to the underlying bone using titanium screws. After 1 week the titanium plate
is elevated, creating space between it and the silicon tissue and allowing the bone to grow. The study focused on effectiveness of this procedure at 2 months and 4 months after elevation of the titanium plate. The surgical method was applied to the cranial bones of 8 white male rabbits of the same species and size. The rabbits were randomly divided into two groups (4 rabbits in each group). One group was euthanized after 2 months, the other after 4 months. The new bone formation (measured in millimeters) around the cranial bone was recorded for each rabbit. The data (simulated) are shown in the table in the next column. The researchers conducted a nonparametric analysis of the data in order to compare the new bone formation distributions of the two groups. Carry out the appropriate test at a = .10.

Group 1 (2 months): Group 2 (4 months): 104.1, 96.7, 73.8 69.7 34.0, 53.6, 62.5, 64.4,