OK, here's one I can't wrap my mind around
Message posted by Aron Pilhofer on February 29, 2000 at 12:00 AM (ET)

It's late, and I am sure there is an easy answer here, but I can't seem to come up with one.

I want to know how a person's chances of succesfully doing a certain thing increase or decrease with age.

How would I determine what size sample I need to test at each age bracket to make sure I have a reasonable level of confidence that the overall results are valid?

I'm just plum stumped on this one.