"My null hypothesis relates to shipping costs being higher for critical orders than low priority orders. So u1 - u2 less than or equal to 0 is null hypothesis and right-tailed t-test. What I am unsure of is which is the best data to use from the excel output? I have t-stat=0.4877, P(Tless/equalt)one-tail=0.3152 and t-critical one-tail=1.717?"