What exactly are we supposed to do for question b?
My understanding is that I need to come up with a graph that is
similar to what Gary had in the slides (the graph that 250 people asked
for). Am I right? How is "First differences" then? How do I draw lines
that represent the confidence intervals? HELP!!!!!
Yes, that's what you are supporsed to do. You are also right that it's not
really "first differences."
Kosuke