### Two sided p-value to compare Group A and Group B

A study was carried out and subjects were randomized to 2 groups: Group A: control diet group, N=154 Group B: a fruit-and-vegetable group, N=154. The 97.5% CI for mean changes in Group B minus mean change in Group A is (-4.7 to -0.9). Suppose we want to compute a two-sided p-value to compare the two groups. Without doing