If you choose a difference hypothesis, Minitab displays the difference between the means and the confidence interval for that difference. If you choose a ratio hypothesis, Minitab displays the ratio of the means and the confidence interval for that ratio. If the confidence interval is completely within the equivalence interval, then you can claim that the two treatments are equivalent.

The generic antacid did not appear to raise stomach pH as much as the brand-name antacid. The mean stomach pH after the generic antacid was approximately -0.321 less than the average pH after the brand-name antacid.

The confidence interval for the difference (-0.42735, 0) falls partly outside of the equivalence interval (-0.42503, 0.42503). Thus you cannot claim that the two antacids are equally effective at raising stomach pH.

The equivalence plot is a useful way to visualize these results.