please solve this

Next two problems Operate with normal approximation to the binomial. There is a rule that states: if Y has binomial distribution (Bin [75, 39]) and a number of trials 11 is large, then approximately Y N N [,u, U], wherepe=E[Y]=n-panda=Vn-p-(1p) Problem 4: 20 points = [5 + 5 + 5 + 5] Consider a large sample of n = 400 students and assume that p = 80% of them will graduate within next three to four years. 1. Find the approximate probability that at least 312 of them will graduate within the next three to four years. 2. Determine the approximate chance that number of those graduating within next three to four years is below 324 and above 312 3. Find yscores that correSpond to z = :|:1.5 and then evaluate the probability that Y will be within the limits you have just found. 4. Assuming that only 5% of standard normal distribution would exceed 2 = 1.645, determine bounds in Y-scale, such that only 5% of Y-values will be below lower bound and only 5% of Y-values will exceed the upper bound. Solution