"Now declare the sample size." what is this for?

[jowens]

Totally unclear to me why we need to declare the sample size or the original table's size. Where is this actually used (please tell me why I need to declare this)? Are these magic variable names that feed into some of the computations below?

[henryem]

It's a hack that we'll soon eliminate. We need to know how large the sample was, so that we can scale up things like SUM and COUNT appropriately. Obviously this should be done automatically, but right now it isn't. Given that it doesn't make a lot of sense, I think it would be more confusing to spend time explaining it. Agree/disagree?

[jowens]

I think a short sentence that says "For the following computations, we need to declare a couple of variables manually; future releases won't require these manual declarations, but in the meantime, bear with us and declare them as follows:" might be helpful.