This, That, and the Other Thing

When I was reviewing my notes for an upcoming test, I found this problem. We were asked a question that led to another question that led to more questions.
Problem:
Given a random variable X, find a constant b such that b is a "good" estimate of X. This led to the question:  What is a good estimate? Well a good estimate is one in which the average distance between b and x is small. This leads one to ask: How small is small? and How to I measure distance?  And on and on...
This turned into an entire page proof which you should thank me for not posting :)

On a different (and less sad) note, here's a worksheet that my MAT 114 students did last week. With little formal training in probability, you might be able to answer a question or two.

Again, completely unrelated to anything else in this post, I rolled my ankle on Sunday. I haven't rolled it this bad since 5th grade when I fell (more like the rope I was swinging on broke) down from the hay bales. Anyway, my foot's been practically a rainbow of colors. First it was green, then blue, and how it's kind of purple. The swelling is almost gone and today I could finally walk normally.

I know it doesn't look like it in the picture, but the whole ankle region is a blueish-greenish-purple color. Also I do not normally have cankles...it's swelling.