Chapter 10: Samples, Continued (Days 73-74)

Today, December 2nd, 2021, is a palindrome in the mmddyyyy format, 12-02-2021. It is also part of a Palindrome "Week" in the mm-d-yy format, 12-1-21 through 12-9-21.

Today in Stats, we continue with the next six pages in Chapter 10, on samples. These pages cover some of the problems with sampling -- particularly voluntary response bias. With self-selected respondents, often only certain people choose to respond to a survey, which invalidates the results. As an assignment, I have the students use simple random sampling to select from the list of the 1000 most common English words. By doing so, the students get to use the random number chart in the text as opposed to the randInt function on the TI calculator.

During tutoring, I ask the girl with the lowest grade to stay an extra hour. I help her with this week's assignments, and we go over the most recent test, on which her score was 45%. In doing so, we spot an error on one of the questions where I accidentally included an extra minus sign (and hence I implied that the number of sales of a certain song is always negative). Because of this, I end up raising her score to 55% -- ten points to make up for the faulty problem.

Speaking of 55%, in Calculus class, the girl who finally made up her test also earned that score. Of course, she's owed the opportunity to do test corrections. I'm not going to make that mistake again where the absent students don't get the chance to remediate their grades.

Unfortunately, my Calculus lesson itself has a few mistakes in it. First of all, when I chose two questions from the AP Question Bank for Assignment #60 last time, one of the questions was in fact a related rates problem -- but we don't reach related rates until Chapter 4 (and hence second semester). Thus the previous assignment contains only one valid question -- which I reviewed as the Warm-Up. In order to avoid that error, today I return to doing problems from the book. I start out with finishing numerical derivatives from last time, then return to Section 3.2, on the product rule. This time, I assign problems #41-50 from the section (odds Assignment #61, evens Assignment #62). These are the same one that the experienced teacher assigned at the main high school. Again in line with the AP exam, these questions cover all four ways to express functions -- numerically, graphically, algebraically, and verbally. Each problem requires taking a function in one of these four forms and using the product or quotient rules to find the derivative.

Most of the lesson goes well, although my example for verbal isn't the best example -- after all, it's very difficult to come up with a good word problem from scratch. I try to reword the Warm-Up question (on shoppers and their purchases), but I stumble with the wording. Indeed, with word problems more than any other type, I might have to break down and just give a problem from the book verbatim.

Meanwhile, in Ethnostats, I started the McFarland movie yesterday, and I'll finish it tomorrow. The lone Cross Country runner in the class says that he's heard of the movie before. He seems to enjoy it, but I admit that he was distracted with last-minute college applications (with the deadline extended an extra day at the Cal State and UC systems due to computer issues). I'll assign discussion questions the tomorrow.

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