its certainly possible for the lower scores, but what im saying is that its not possible for the higher scores. scoring 90 at medentry wont mean u will get 100. at the top end in the actual umat, a lot comes down to luck. e.g. you may waste all ur time on a "test" question, you could correctly guess a high mark question (huge boost to ur score) or you could waste time on a low mark question. medentry exams dont account for these things.
on a side note, keep in mind that theres only so far prep can take you. you can increase ur score up to a certain point where it is then limited by your own ability/IQ/EQ. its similar to running. when you are just starting, you may run a race in 20 seconds. you train and the next day you can do it in 15. then 13, then 12, then 11.5 11.3 etc etc. when you are reaching ur peak performance, the improvement diminishes each time.