Lt x be a random variable with px - 1 px 0 14 and px

Question

Let X be a random variable with P(X = - 1) = P(X = 0) = 1/4, and P(X = 1) 1/2 , Let S be the sum of 25 independent random variables, each with the same distribution as X. Calculate approximately a) P(X < 0),="" b)="" p(s="0)," and="" c)="" (s=""> 0).