Uncle Henry has been having trouble keeping his weight constant. In fact, at the end of each week

Uncle Henry has been having trouble keeping his weight constant. In fact, at the end of each week, he notices that his weight has changed by a random amount, uniformly distributed between -0.5 and 0.5 pounds. Assuming that the weight change during any given week is independent of the weight change of any other week, find the probability that Uncle Henry will gain or lose more than 3 pounds in the next 50 weeks