20. Seventy patients with stasis ulcers of the leg were randomly divided into two equal groups. Each group received a different treatment for edema. At the end of the experiment, treatment effectiveness was measured in terms of reduction in leg volume as determined by water displacement. The means and standard deviations for the two groups were as follows:

Group (Treatment)

A 95 cc 25 B 125 cc 30 Construct a 95 percent confidence interval for the difference in population means.