Let T be the random time when a random walk first hits either the point x = 2 or -2. That is: T=T1 = min {n: Sn=2} Please find the probability distribution and the expected value of 7. Hint: You can consider consecutive pairs with a 'size of 2' such as (1,1),(-1, -1) and consecutive pairs such as (-1,1), (1, -1) separately and get help from first success probability. (You don't have to of course, as long as you solve the question any method is great.) Let T be the random time when a random walk first hits either the point x = 2 or -2. That is: T=T1 = min {n: Sn=2} Please find the probability distribution and the expected value of 7. Hint: You can consider consecutive pairs with a 'size of 2' such as (1,1),(-1, -1) and consecutive pairs such as (-1,1), (1, -1) separately and get help from first success probability. (You don't have to of course, as long as you solve the question any method is great.)