MIT 6.041SC Probabilistic Systems Analysis and Applied Probability, Fall 2013 View the complete course: http://ocw.mit.edu/6-041SCF13 Instructor: Kuang Xu ...
========== In this problem, we'll be
working with a object called random walk, where we have a
person on the line-- or a tight rope, according
to the problem. Let's start from the origin, and
each time step, it would randomly either go forward
or backward with certain probability. In our case, with probability
P, the person would go forward, and 1 minus
P going backwards. Now, the walk is random in the
following sense-- that the choice going forward or backward
in each step is random, and it's completely
independent from all past history. So let's look at the problem. It has three parts. In the first part, we'd like to
know what's the probability that after two steps the person
returns to the starting point, which in this
case is 0? Now, throughout this problem,
I'...