# AP Statistics Assignment for 9/13

Over the weekend, write your response for the Chapter 2 Investigative Task (Race and the Death Penalty). As noted in the document, you may use your textbook and notes to help you write your response, and you may use the Internet to access Google Docs and Stapplet or whatever other graph-making tools you want to use, but you may use no other resources other than those. Do not go online looking for more information, and definitely no working with other students on this assignment.

Your response should be completed in a Google Document and submitted to me (bkirk@icsd.k12.ny.us) by the start of class on Monday, the 16th. Please name your file appropriately; it should have the format “LastName.FirstName.Ch2InvTask”.  For example, mine would be “Kirk.Benjamin.Ch2InvTask“.

Because some folks have asked, you can find instructions on taking screenshots using a Chromebook here. I recommend the Ctrl+Shift+Window Switch shortcut to take a screenshot of only the particular items you want to use.

# AP Statistics Assignment for 9/11

In class today, we will be looking at conditional displays of data, including segmented bar charts and mosaic plots. Visit www.stapplet.com for some easy-to-use tools on creating these displays. We will also be looking at this mosaic plot worksheet.

Tonight, read pages 24-32 (finishing chapter 2).

From page 39 (ch 2), do 25, 27, and 29.

# AP Statistics Assignment for 9/10

From page 11, do exercises 15 and 16

From pages 36-39, do exercises 11, 13, 17, 23

# AP Statistics Assignment for 9/9

Visit this post from the beginning of the year for the Student Information Survey and Textbook Log Form.

Also, I need everyone to register for the online AP Classroom for messages and occasional assignments. Sign in to myap.collegeboard.org (use the same login you use to access prior AP scores or to register for the SAT) and click “Join a Course or Exam” and use the code 9XKQKJ (period 1) or KWKAJG (period 7) to register for the class.

Tonight, please read Chapter 1 (pages 1-9) of your textbook. Skim it if you don’t have time to read it closely, but work on questions 1, 3, 9, and 13 from pages 10-11.

Finally, look over the student survey results and identify 2-3 interesting statistics and/or observations you can glean from the data.

# AP Statistics Assignment for 9/5

Complete the Smelling Parkinson’s simulation that we started in class today. Go to the simulation page here and change the settings to match those in the screenshot below (though feel free to tell the simulator to stop at 10,000 trials or “never” to get even more if you’re curious). Record your result for 1000 trials on your paper, and bring it in tomorrow.

If you would like to read the interview with Target’s lead statistician, where I got the story about the father and his pregnant daughter, you can find it here.

# Welcome Students and Parents!

Welcome to my website!  I designed this site to be a simple and useful means for me to communicate with you outside of class. How will this site be useful to you?

## GETTING ASSIGNMENTS/MISSED NOTES

I will post the daily homework assignments (and daily notes whenever possible) here on this site by the end of the school day.  If you are absent from class, either from illness or some other reason, you are expected to come to this site to find out any homework assignments you may have missed.  You will receive extra time to complete them as I discussed in class, but this way you can stay caught up without even coming in!

The comments for every homework post are open and anonymous.  If you ever have questions about any aspect of the homework, come here and make a quick post.  I will check the site often and answer your question as quick as I can.  You don’t need to give your actual name when you post, so don’t feel embarassed about asking!  Besides, I’ve never seen the case where only one person had a particular question; if you’re wondering, somebody else is probably wondering too.

If you want to come get some extra help during the day, see the Class Information page at the top!

## FINDING OUT WHEN TESTS ARE BEFORE ANYBODY ELSE

That’s right!  I will always announce an upcoming test or quiz here on this blog before I announce it in class!  Visit the blog every day so you can plan out your studying and preparation.

In my Statistics class in particular, but occasionally in Intermediate Algebra, we will do a few projects over the course of the year.  Any details about these projects that I give in class I will also post here.  If you forget when a part of a project is due, visit the site and check the post about it!

## PREPARING FOR FINALS

Introduction to College Algebra and AP Statistics both have a major end-of-year test (Fractals and Chaos does not).  Over the course of the year, I will post links, advice, and test taking strategies to help you prepare for these tests.

Finally, any time I come across something interesting about the field of mathematics, I’ll post it here.  It could be a news article, a nifty website, or just something I heard.  The world of math is constantly changing and evolving, despite what you may think.  New strategies of solving puzzles are found, old puzzles are being solved, and those solutions are leading to new puzzles every day!

I hope you will visit this site often, and I look forward to working with all of you this coming year.  Thanks for coming and I’ll see you in class!  Oh, and incidentally, my favorite color is green.

# Mathematical Musing: What is r (Part 2)?

In Part 1 of this question, we explored how the correlation coefficient is calculated, and how that calculation relies heavily on the covariance between two quantitative variables. We left off with a few questions: why is r bound between -1 and 1, and why does a value of r near 0 indicate a weak association (and near an extreme indicate a strong one)? In this post, we will answer these questions!

# Mathematical Musing: What is r?

A student asked me a really interesting question recently; a pair of questions, really. We have just discussed the correlation coefficient as a measure of the direction/strength of a linear association between two quantitative variables, and I demonstrated in class that the calculation for this quantity, referred to by the letter r, can be found by the formula

In other words, for each point of a scatterplot, find the z-score for the x-coordinate and the y-coordinate of that point and multiply those together. Do this for all of the points in your scatterplot, add them together, and divide by n-1 to get your correlation coefficient.

We discussed various properties of this quantity, and my student asked me that question that teachers always hope for (if not without a bit of dread sometimes!): “Why?” Why does this formula produce a quantity that measures the strength of a linear association? Also, why must the value of r necessarily be bound between -1 and 1? In this post, I seek to start an answer to these questions.