Chebshev probability, central limit theorem

(4) Suppose that an ant is placed on a tape. It randomly decides to move forward 1 inch, or backwards 1 inch. After 1 second, it reaches a new location, and then randomly moves forward 1 inch, or backwards 1 inch, and so on. Assume that each move X,- is uniform in {1, +1}, and that the X, are independent. Use Chebyshev (in the form of the corollary of the weak law of large numbers) to give an upper bound to the probability that the ant has travelled at least 5 inches in either direction in 10 seconds. (5) Estimate the probability in the last problem using the central limit theo rem. You can leave your answer in terms of the function E)