In study of 200 subjects with acute ankle sprains were tested to compare two treatment methods, one (called Treatment) with oxygen at 1.2 atmosphere absolute pressure and the other (called Control)…

In study of 200 subjects with acute ankle sprains were tested to compare two treatment methods, one (called Treatment) with oxygen at 1.2 atmosphere absolute pressure and the other (called Control) with air at 1.9 atmosphere absolute pressure in hyperbaric chamber. The subjects were divided equally in a double-blind manner between the two methods of treatment. A seven points Ankle Function Score (AFS) was tested to evaluate the effectiveness of each method and higher AFS indicates higher level of recovery. At the end, the following information was gathered.

Control
Treatment
Number of subjects
100
100
Mean AFS
5.4
6.5
Standard deviation of AFS
0.8
0.6

Using 5% level of significance, test whether treatment is better than control.