Students,

I have figured out why there was more than the usual amount of confusion
on the homework problems I assigned for Thursday. The four problems I had
thought reasonable from Chapter 7 are, in fact, right there in Chapter 7 ...
in the section marked "Theoretical Exercises"! I didn't realize I had
slipped out of the "Problems" section.

So I will offer you two things.

1. For any of those four questions, you should feel free to do either
the "Problem" (which you may already have started) or the "Exercise" that
I had intended you to do (and which may be easier for you).

2. The conditional expectation problem 7.55 is pretty interesting but
hard enough that it even took me a little while to remember how to do it,
so that one I'm just going to give to you. I'm writing up a solution that
I think you will find informative and putting it on my website 
( math.utexas.edu/~rusin/362K/ )

I'm very sorry about the confusion and will instruct the grader to be
lenient in the scoring. But remember, the main point of the homeworks is
not so much the getting of a good score as it is about trying to solve
good, meaty problems. So give some thought to both sets of the four
questions!

dave