For any randomized trial, some variation from the mean is expected, of course, but the randomization ensures that the experimental groups have mean values that are close, due to the central limit theorem and Markov's inequality.
Ye irum kul ijan, amutiy iyan as awa ogdahən eqal atiwaqalan, mashan tijjit tigozst as gruɗtan oramnen ilan tamɣare ogdahnen anehaznen, as adatu ən tamkare namas təmdat ad anəmijar ən Markov.