Wednesday HW!

Tonight you'll be reading/learning more about experiments!


Tomorrow in class we'll start with a "bias" stamp, then we'll get into the experimental design stuff! The plan is to cover experimental design (quickly) and finish on Monday, with a test on Tuesday!


The test Tuesday will be half vocab and half AP problems; it will cover sampling methods and experiments!


Until then, tonight please answer the following questions in your "Chapter 13 Project: Teaching Yourself Experiments and Observational Studies" (Feel free to record these answers as an outline in your notes if you like, or on the handout provided):


4, 5, 6, 7, 17, 18


And of course tomorrow you'll have to finish the rest--feel free to do those as well!


11, 12, 13, 14, 15


Have an awesome Wednesday! See you tomorrow!

Back to Work!

Tonight (Tuesday) please complete the following from your "Chapter 13 Project: Teaching Yourself Experiments" questions: 

 1abc, 2, 3, 8, 9, 10, 16

And since this is the first homework of the new quarter it counts double!

If you lost your copy of the questions (or you were out) you can find them under our classroom powerpoints and assignments link OR in the blog post below!

If you're feeling ambitious feel free to answer more of these questions! You will have some to answer each night, so if you do them all today you'll have a lot of your homework done for the remainder of the week!

Next Week's HW and Grades in!

Midterm exam grades and quarter grades are in! 

• Please double check your stamp grades! If the total is not correct, send me a Remind or email by Monday (carofano.fm@easthartford.org)
• Your exam grade correlates to your predicted score on the AP Exam!
• A = projected 5, B = projected 4, C = projected 3, D = projected 2, F = projected 1
• Further, the numeric score gives you an idea of how close you were to earning the next highest score
• For instance, if you got an 88, you are projected to earn a 4 but were close to getting a 5!
• We will discuss this all more moving forward

Next week (Tues, Wed, Thurs) you will have to teach yourself chapter 13 for homework!

• Each night you will be given certain questions to answer based on reading your textbook (ch 13)
• You may also be given a textbook problem or two to do along with the questions you answer!
• So, the more you get done this weekend, the easier your week will be!
• If you'd like to get a head start--and maybe do all of this work this weekend, so you have a lot less to worry about next week--all of the questions you'll have to answer are uploaded under the "Classroom Powerpoints and Assignments" link on the right!
• You can either print out a copy of these questions using the word document from the classroom powerpoints and assignments link...
• Or you can record all of this information in your notes...
• Or you can stop by and grab a hard copy of these if you're in school tomorrow or Monday...
• Or you can wait until Tuesday and just do the assigned homework each night!

Or, you can find the questions for next week here:

Read the chapter (13) and complete each of the questions below. Remember, this is for your benefit; the more thorough your notes/responses are, the better prepared we will be! This will be counted as a classwork grade!

·         These questions only serve as an outline to help guide your reading. Of course you can take additional notes to strengthen your understanding!

1.       There are two types of observational studies—retrospective and prospective studies.

a.       What is a retrospective observational study?

b.      What is a prospective observational study?

c.       What is matching in an observational study? (page 305).

2.       In an experiment where does the random assignment occur?

3.       What is/are the factor(s), levels, and treatment(s) in an experiment? Define each.

4.       What is the response variable?

5.       What distinguishes an experiment from the other methods of data collection? In other words, how is an experiment different than a simulation, sample survey, and observational study? (This is in your notes from our first day on “methods of data collection….”)

6.       Describe/comment on each of the four principles of experimental design:

a.       Control:

b.      Randomize:

c.       Replicate:

d.      Block:

7.       What sampling method is equivalent to blocking in an experiment?

8.       *Be sure to read through the step-by-step examples in the chapter; these are the examples we would have discussed for our notes in class!

9.       Complete each of the “just checking” questions on page 301 (parts a-e). Record your answers/work below.

10.   Explain the meaning of “statistically significant.”

11.   What is a control treatment/control group?

12.   What does it mean for an experiment to be single-blind or double-blind?

13.   What is a placebo? Why do we use placebos?

14.   Complete the “just checking” questions on the bottom of page 305 (parts a-c). Record your answers/work below.

15.   What does it mean for two variables to be confounded?

16.   In your own words summarize the procedure for the tomato/fertilizer experiment diagrammed the bottom of  page 299.

17.   Now look at the blocked version of this tomato/fertilizer experiment diagrammed on page 305. In your own words, how is this blocked version of the experiment different from the original version (on page 299)?

18.   Finally, examine the diagram of the 2-factor version of the tomato/fertilizer experiment on page 306. What are the two factors being manipulated here? For this experiment, describe/identify each of the following:

a.       Factors (2):

b.      Levels (for each factor):   

c.       Treatment groups (6):

19.   Note the vocabulary list on page 310-312. This list shows the words that you are responsible to know! 

So here's the plan when we're back...

• Tuesday = discuss exams, AP stuff, and bias!
• Wednesday = bias and sampling wrap up
• Thursday = experimental design
• Friday = experimental design!

Study, study, study, stuuuudyyy........stuuuuuuuuuuuudy! (Updated again Saturday)

This weekend and upcoming week are all about the midterm exam! It is essential that you prepare yourself to succeed on your midterm! The midterm exam is a mini AP exam, so it gives us our first "real" prediction about how we might score in May! Prepare yourself just as you will for the AP Exam! I'm looking forward to you all making me proud next week! :) 

• There is an outline of the midterm exam topics under the "Classroom Powerpoints and Assignments" link on the right! (60 min = 28 MC, 60 min = 5 FR)
• Look over this list and identify your strengths and weaknesses!
• Then, use your Barron's book to review/practice the skills you need to work on!
• Use the table of contents to find specific topics and review/practice those skills!
• Then, use some practice exams in the back of the book to get ready for the AP Exam!
• Here's a list of the questions you can do for Practice Exam 1 in the back of your Barron's book:
• MC: 1,2, 3, 5, 6, 9, 10, 13, 16, 18, 19, 20, 21, 24, 25, 27, 28, 30, 31, 33, 34, 38, 40
• FR: 1
• You can also do the following from the free-response section of Practice Exam 2:
• FR: 2, 3, 5
• Here are some other suggestions/ideas for studying:
• Look over your unit tests! These tests summarize many of the "main ideas" from each chapter!
• Look over your past quizzes!
• Read through your notes--maybe even create an outline (handwritten/typed) that summarizes all of your notes! Then you'll be doing lots of studying by creating the outline, and you'll have the outline to read over on the bus or as you walk to school or whenever you have free time! (This is how I studied for lots of stuff in college)
• You'll also have this outline to look back at for the AP exam!
• Work with your classmates/friends--have a study group hangout!
• Some of the things you need help in might be a friend's strength (and vise versa)! Work together and help each other!
• Watch AP Stats Guy (and other) videos to refresh your memory on various concepts!
• Go to the link below for all of the released Free Response with their scoring rubrics!
• All Released AP Stat Free Response Questions and Rubrics!

Update After I Finalized Our Exams -- A Few Specifics to Study....

• I just put the finishing touches our our midterm (it's a masterpiece)!
• Here are some specific things you should be sure to review that may not have shown up in our midterm review stamps--this is NOT a list of all the content on your exam, just some specifics you definitely want to review!
• Be sure you know the difference between stratifed, cluster, and simple random samples and how to write "procedures" for each
• Look over the 2011 Free Response we discussed in class on Friday (about apartments)--look at the rubric online! (link above)
• Study normalcdf (to find % or probabilities) and invnorm (to find a cutoff for a given percentile)!
• Shifting and Rescaling!
• Be sure you know how to create stemplots (or back to back stemplots), boxplots, and histograms!
• Combining random variables to find a "new" standard deviation--Pythagorean Theorem of Stats!
• What is standard deviation? What does it measure?
• Know how to interpret slope, y-intercept, and R^2!
• Review leverage, residual, and influential points!
• Calculate residuals! (or, find an actual value given an equation and a residual)
• Know how to determine if a linear model is appropriate
• Study all of your probability!
• Conditional, expected value, binomial/geometric, look over the "airlines" problem (a stamp)
• Review all of your sampling methods (again) based on our sub work!
• Be sure you understand the "number breakdowns" for simulating with a random number table!
• Understand what population a sample represents!
• Be sure you can create a scatterplot given some data and describe the association seen in a scatterplot!
• Practice writing everything in context--be specific and detailed, but also be concise! No fluff or "extra stuff!"

And finally, remember....

• Stamps are due by the day of your exam! (but just get them in tomorrow!)
• Count up your stamps...twice (double check)
• Fasten them together/put them in an envelope/bag/something...
• Write your name and the total on the front
• Double check!
• I will randomly select 5 or 6 students per class and double check your count...if it's off you get a 0!

Last Homework of the Quarter!

Tonight, please complete the problems below (in your textbook or on the handout provided in class)--our last homework assignment for the quarter!

Page 290: 11, 12, 13, 15, 27

**And since this is our last homework assignment of the quarter it's going to count double!**

Here's some more stuff to keep in mind....

• Stamps are due by the day of your exam! (but just get them in tomorrow!)
• Count up your stamps...twice (double check)
• Fasten them together/put them in an envelope/bag/something...
• Write your name and the total on the front
• Double check!
• I will randomly select 5 or 6 students per class and double check your count...if it's off you get a 0!
• There is an outline of the midterm exam topics under the "Classroom Powerpoints and Assignments" link on the right!
• Look over this list and identify your strengths and weaknesses!
• Then, use your Barron's book to review/practice the skills you need to work on!
• Use the table of contents to find specific topics!
• Then, use some practice exams in the back of the book to get ready for the AP Exam!
• Here's a list of the questions you can do for Practice Exam 1 in the back of your Barron's book:
• MC: 1,2, 3, 5, 6, 9, 10, 13, 16, 18, 19, 20, 21, 24, 25, 27, 28, 30, 31, 33, 34, 38, 40
• FR: 1
• You can also do the following from the free-response section of Practice Exam 2:
• 2, 3, 5

And lastly, here are the homework answers so you can check (of course they're also in the back of the book...)

• 11.) Parent Opinion, Part 1
• a. Voluntary Response Sample; 
• b. Cluster Sample (but not a good idea); 
• c. Attempted Census; 
• d. Stratified Sample
• 12.) Parent Opinion, Part 2
• a. Voluntary Response Sample; 
• b. Voluntary Response Sample (b/c only those who choose to attend will respond); 
• c. Cluster Sample (maybe multi-stage, if we consider each school a strata, then we consider a classroom within a school a cluster); 
• d. Systematic Sample
• 13.) Churches
• a. Multi-stage (start with cluster by randomly choosing 3 churches, but then SRS from each cluster that was selected); 
• b. If any of the 3 churches you pick are not representative of all churches, then your sample will not be representative of the population. Also, if we choose 100 people from each church, we may over-represent larger churches or under-represent smaller churches, and people from large/small churches may have differing views.
• 15.) Roller Coasters
• a. Systematic Sample
• b. This sample would not represent all people at the park (parkgoers). Since we only sampled people in line, we might over-represent people who do not mind waiting (as they clearly don't mind staying in line).
• 27.) Accounting
• a. Could use a simple random sample...
• Put the name/number of all 120 orders on a piece of paper...
• Put these names/numbers in a hat
• Mix up the papers (randomize).
• Select 10 papers and check those 10 transactions to see if they were processed properly.
• ORRRRR...
• Number each order from 001 - 120 (or 1 - 120).
• Use a random number generator to generate 10 random numbers from 1 - 120, ignoring repeated numbers.
• Check the 10 orders whose numbers were generated to see if they were processed properly.
• b. If we had wholesale and retail sales we should now use a stratified sample...
• Split the orders into strata--wholesale orders and retail orders
• Then, randomly select some number of wholesale and some number of retail orders (we want our sample to reflect the proportions of wholesale/retail orders amongst all 120 orders).

Sub Work Tomorrow/Wednesday HW!

Three more days of hard work before our exam! (Well, three days of work in class...of course you'll be working hard on your own to prepare for the midterm!)

Remember, there is an outline of the topics on our midterm exam under the "Classroom Powerpoints and Assignments" link on the right!

• Then use your Barron's book for lots of practice!

Tonight (Tuesday) "Homework":

• Remember, stamps are due on the day of your exam!
• But....you can turn them in early!
• If I were you I would count up all my stamps, record the total on the front, and turn them in on Thursday--then you're done with them!
• Remember to double check your counting, as I will randomly sample 5 students from each class to double check! 
• If you're total is wrong you get a 0!
• Study for your midterms!
• And if you didn't do the extra credit from the weekend homework (check your answers) you can do so for Thursday!
• Read the blog post below!

Tomorrow in class you will be given some new notes about sampling methods; then you will complete some short answer and some multiple choice questions regarding these methods!

• First you will be given an outline of the sampling methods; you should read through this, summarize the info, and record it into your notebook in your own words
• I will check for these notes (in your notebook) when I return on Thursday! This will count as a classwork grade!
• Next, you will have some short answer and multiple choice questions--identifying sampling methods.
• Both classwork assignments will be collected and graded.
• Finally, you will have 10 multiple choice questions for homework!

Finally, if you're feeling super ambitious tomorrow (Wednesday) night, here's Thursday night's homework--our last homework assignment for the quarter!

Page 290: 11, 12, 13, 15, 27

*I will give you a handout with these questions in class on Thursday as well. 

Weekend HW--Updated Monday with EC Opportunity!

This weekend please complete the two midterm review "stamp problems" (but they're not stamps anymore) and the sampling questions provided in class (or below)!

And here are the homework answers so you can check yours--of course we want to make sure we're practicing correctly when we study!

**If you check over your answers and make any corrections/comments on your original response you can earn homework extra credit! Just show evidence (notes) that you checked over all of your reponses!**

Stamp: Linear Regression (Given Computer Output):

• Slope: According to the linear model, for each additional 1 hour a student spends studying, his/her predicted final exam score increases by approximately 2.697 points.
• Y-Intercept: According to the LSRL, if a students studies for 0 hours (if a student does not study), his/her predicted final exam score is roughly 62.328. (This is realistic).
• Coefficient of Determination = R^2: According to this model, about 56.7% of the variation in exam score can be explained by the changes in study hours. Other factors might include the student's course grade/performance and the difficulty of the exam.
• Residual = Actual - Predicted
• Actual score = 84
• Predicted score = 62.328 + 2.697(6) = 78.51
• Residual = 84 - 78.51 = 5.49.
• (This residual tells that we underestimated the final exam score for a student who studied for 6 hours by 5.49 points; remember, a positive residual is an underestimate).

Stamp: Probability (Spinner Question)

• a.) P(lands on # divisible by 3) = 3/10 = 0.3
• We have 3 numbers divisible by three on the spinner: 3, 6, and 9 out of 10 total sections.
• b.) P(all 6 spins land on a # divisible by 3) = (0.3) ^ 6 = 0.000729
• Remember, 7.29E-4 means you have to move the decimal 4 places to the left; this is the calculators form of scientific notation
• If you're stuck, write it out in words! 
• "divisible by 3" and "divisible by 3" and "divisible by 3" and......
• c.) P(not all 6 spins are divisible by 3) = 1 - (0.3)^6 = 0.999271
• Focus on the question..."not all 6 spins are divisible by 3"
• Not = 1 - 
• First, we'll find the probability "all spins are divisible by 3" 
• Then, since we want "NOT all spins are divisible by 3" we'll subtract this answer from 1!
• On our probability test many students tried this: (0.7)^6; this is incorrect, because this represents the probability that all the spins are not divisible by 3, which is a different situation
• "not all divisible by 3" means they are not all divisible by 3; in other words, 0,1,2,3,4 or 5 spins can be divisible by 3, just not all of them
• "all not divisible by 3" means all of the spins are not divisible by 3; in other words, none are divisible by 3!
• d.) P(spin 50 times and at most 10 spins divisible by 3) = bincomcdf(50, 0.3, 10) = 0.0789
• Remember binomcdf is used for "cumulative" probabilities, or numbers of outcomes "below" or "to the left" of what we enter for our x value (10 in this case)
• Binompdf would give us the probability that exactly 10 spins land on a number divisible by 3....
• e.) P(first spin divisible by 3 is 4th spin) = (0.7)^3 * (0.3) = 0.1029
• OR, geometpdf(0.3, 4) = 0.1029
• If you're stuck here, just go back to your words!
• "not divisible by 3" and "not divisible by 3" and "not divisible by 3" and "divisible by 3"

Sampling Context: The Gallup Poll and TV...

• Population = all American citizens
• Population Parameter of Interest = % of all American citizens who identify each type of content that bothers them the most (% of all American citizens who are bothered by violence, by language, or by sexual situations)
• Sampling Frame: all American citizens with a phone
• Sample: the 1,475 Americans who were randomly called and surveyed
• Sampling Method: randomly generated phone numbers (this is a simple random sample, which is essentially "pulling names out of a hat"
• Yes, we can generalize our results to the population of "all American citizens" because the sample was collected randomly (simple random sample) and therefore should be representative of the population.

This is also a great time to start studying for your midterm!

• Use your Barron's book! Look over different topics we've learned and try a practice exam!
• Look over your take home test (passed back today) and figure out anything that was incorrect!
• Use your notes to review!
• Look at the outline of topics under the classroom powerpoints and assignments link on the right!

Tuesday in class we'll get back to our sampling methods! See you there!

Then, on Wednesday we'll have some classwork to do (I will be absent unfortunately) that will be graded. Finally, on Thursday and Friday we'll talk more about sampling and bias before the midterm! See you there!

Have an awesome 3 day weekend!