Chapter 7 Intro: This chapter is about understanding "sampling variability" and "sampling distributions", which will allow us to move on to more types of hypothesis tests.
Before you get started: Go back and review your notes on Buzz and Doris, from Chapter 5.
So, going back to Buzz and Doris, remember that we were trying to figure out how we could tell whether Buzz was just guessing vs. whether he and Doris were actually communicating. We had to understand how likely it was that he would get 15 out of 16 "guesses" correct. When we found out that there was a very, very, very small probablillty that he could have chosen the correct door 15 times, we decided the more reasonable explanation was that he was NOT guessing.
So that bit about the probability, remember that we looked at how random chance works, what are likely outcomes with 16 coin flips, and what are not, in terms of how many heads you'd get. That led to a probability distribution of outcomes, with 8 heads being the most likely, 7 or 9 heads also pretty likely, but getting only a few heads or lots of heads was pretty unlikely. This is the heart of what we'll be learning about in this chapter!
Section 7.1. Surveys
Before we get into the concept of sampling distributions, we need to learn a bit about how to get or identify good samples vs. bad samples and, most importantly, what a Simple Random Sample is.
Blank Notes (print these out before you begin)
Filled-in Notes (for reference*)
*The video is still pretty awkward but at least I now have a touch-screen laptop so I can fill in the notes with screen capture. I'm still waiting for a decent stylus to arrive in the mail. This transition to online is my personal Everest!