Need help with the following probability question:

Problem 5. (20 points) Suppose Y\" is the price of a stock on the nth day, and for all n 2 1 Yn : Ynl + Xn where X1,X2, are iid random variables with mean 0 and variance 02. If the price of the stock today (day 0) is 1001 you want to estimate the probability that the stock will be worth at least 120 on day 30. a) Use Chebyshev's inequality to nd an upper bound on P{Y30 2 120|Y0 : 100}. b) Use the Central Limit Theorem to estimate P{Y30 2 120|Y0 : 100}. Your final answer should be in terms of (I), the GDP of the standard normal