Postoperative ileus (POI) is a form of gastrointestinal dysfunction that commonly occurs after abdominal surgery and results in absent or delayed gastrointestinal motility. Does rocking in a chair after abdominal surgery reduce postoperative ileus (POI) duration? Sixty-six postoperative abdominal surgery patients were randomly divided into two groups. The experimental group (n = 34) received standard care plus the use of a rocking chair while the control group (n = 32) received only standard care. For each patient, the postoperative time until first flatus (days) (an indication that the POI has ended) was measured. The results are tabulated below.

Here is computer output for a t test.
t = - 3.524, df = 63.99, p-value = 0.000396
alternative hypothesis: true difference in means is less than 0
(a) State the null and alternative hypotheses in context.
(b) Is there evidence at the level of α = 0.05 that use of the rocking chair reduces POI duration (i.e., the time until first flatus)?
(c) Although the researchers hypothesized that the use of a rocking chair could reduce POI duration, it is not unreasonable to hypothesize that the use of a rocking chair could increase POI duration. Based on this possibility, discuss the appropriateness of using a directional versus non-directional test.

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Time until first flatus (days) Mean (days) SD Rocking 34 3.16 0.86 Control 323.88 080