For the simple symmetric random walk pSnqn0,1,2,... with S0 0, show that PrS4 0s PrS3 1s (i) with using the probability mass functions of S4 and S3 from class, (ii) without using the probability mass functions of S4 and S3 from class. Hint: In this case, use the fact that PrS3 1s PrS3 1s due to symmetrie of the symmetric random walk (see also Problem 5.2).