Search This Blog

Thursday, March 31, 2016

Thursday HW = Ch. 22 Recap!

Tonight, please complete the "Chapter 22 Quiz B" worksheet provided in class (or below).

In addition to completing 1 (2 prop z test) and 2 (two prop z int), please ALSO DEFINE TYPE I and TYPE II ERRORS ON THE BACK!

Tonight's homework--a hypothesis test, interval, and defining each type of error--recaps everything we need to know from chapter 22! So be sure to do it!


This will count as our first homework grade of the 4th quarter. So let's count it as triple homework! Each question = one homework assignment!

Tomorrow we'll start class with a MC quiz--surprise! This will be your first grade of the 4th quarter! After that, it's on to chapter 23! See you there!


Finally, remember that STAMPS DUE TOMORROW! Last chance to turn them in! Count them up, write the total on the front, and fasten them together/put them in an envelope or something!
  • Remember, only papers that are actually stamped count! If you sneak in papers that weren't stamped you'll earn a 0 for your stamps! I'm checking!

Wednesday, March 30, 2016

Wednesday HW

Tonight, please complete the following in your textbook:

Page 509: 15, 19, 21

  • For the "math" parts of the hypothesis test use your calculator to record the z-score, p-value, and p-hat pooled; tomorrow we'll look at how we "show the work" for this test!
  • Remember, you won't have classwork time for practice, so all of your practice comes from your homework! We'll have a take home quiz this weekend!
  • Our only classwork will be a (short) MC practice to start class on Friday!
Also, remember that STAMPS are DUE TOMORROW! Count them up, write the total on the front, and fasten them together/put them in an envelope or something!

  • Remember, only papers that are actually stamped count! If you sneak in papers that weren't stamped you'll earn a 0 for your stamps! I'm checking!
Here are the homework questions!

15.) A San Diego reproductive clinic reported 42 live births to 157 women under the age of 38, but only 7 live births for 89 clients aged 38 and older. Is this strong evidence of a difference in the effectiveness of the clinic's methods for older women?

a.) Test an appropriate hypothesis and state your conclusion.
b.) If you concluded there was a difference, estimate that difference witha  confidence interval and interpret your interval in context!

19.) In 2001, one county reported that among 3132 white women who had babies, 94 were multiple births. There were also 20 multiple births to 606 black women. Does this indicate any racial difference in the likelihood of multiple births?

a.) Test an appropriate hypothesis and state your conclusion.
b.) If your conclusion is incorrect, which type of error did you commit?

21.) It's widely believed that regular mammogram screening may detect breast cancer early, resulting in fewer deaths from that disease. One study that investigated this issue over a period of 18 years was published during the 1970s. Among 30,565 women who had never had mammograms, 196 died of breast cancer, while only 153 of 30,131 who had undergone screening died of breast cancer.

a.Do these results suggest that mammograms may be an effective screening tool to reduce breast cancer deaths?
b. If your conclusion is incorrect, what type of error have you committed?

Tuesday, March 29, 2016

Tuesday HW

Tonight, please complete the following in your textbook:

Page 508: 3, 5, 7

  • (Last night you started 5 and 7...tonight, finish them! (Interpret your intervals and then answer part c for #7; also, complete all of #3!)
  • For 5A: Remember, standard error is just the estimated standard deviation based sample statistics--so to answer 5A, we simply need to substitute the correct values into the formula for standard deviation from our formula sheet
We will start chapter 23 on Friday, which means we WILL NOT have any classwork on chapter 22--all of your practice will come from your homework! So do it!

Also, remember that STAMPS are DUE starting TOMORROW! Count them up, write the total on the front, and fasten them together/put them in an envelope or something!
  • Remember, only papers that are actually stamped count! If you sneak in papers that weren't stamped you'll earn a 0 for your stamps! I'm checking!

See ya'll tomorrow for a 2 prop z test!


Monday, March 28, 2016

Monday HW!

Tonight, please complete the following in your textbook:

Page 507: 5ab (for b, do conditions and math), 7ab (for b, do conditions and math)

If you want to get a head start, here's tomorrow's homework--you know how to check the conditions and do the math for #3...

Tuesday HW: Page 507: 3, 5, 7.

Remember, ALL MAKEUP MUST BE DONE BY THE END OF THE DAY (AFTER SCHOOL) THURSDAY!

And STAMPS are DUE WEDNESDAY/THURSDAY/FRIDAY!

Thursday, March 24, 2016

Happy Easter + HW!

First and foremost, enjoy your 3 day weekend! Happy Easter!

This weekend, please complete the 15 multiple choice questions (review) provided in class! This is you studying for the AP exam!

Each of the 15 questions is about linear regression; use your notes from October-ish to ace this thing! All of this content can be found in chapters 7, 8, 9, and a tiny bit of 10!

These will be collected and graded on Monday! This is a major grade and one of our last opportunities to boost our average before then end of the quarter  (Friday)--so take advantage of it! Use your notes and your textbook, along with online resources, to do some real studying/review and ace this thing!

If you lost yours or were absent the questions are below--you can record your answers and work on separate paper--get it done!








Wednesday, March 23, 2016

Test Tomorrow!

STUDY, STUDY, STUDY! Tomorrow's test is our most weighted test of the quarter!

Here's a breakdown of what's on your test:

  • Conduct a hypothesis test! (hypotheses, conditions, math, conclusion! (ch. 20)
    • Remember, if you are asked to "show statistical evidence," that evidence is the hypothesis test--all 4 parts!
    • Also, remember that if you're given an alpha/significance level, this is a hint that it's a hypothesis test!
  • Create a confidence interval! (conditions, formula with interval, interpret interval) (ch .19)
    • Remember, if we have to "estimate a percentage" that means we have to create an interval--all 3 parts!
    • Also, remember that if you're given a confidence level, this is a hint that you need to create an interval!
  • Be sure you know how to use your graphing calculator to create intervals and conduct hypothesis tests! (one proportion z interval, one proportion z test)
  • Know how to use a confidence interval to "test a claim" (ch. 21)
    • Look to see if the value falls within your interval!
  • Define Type I and Type II error, along with a consequence of each! (ch. 21)
    • Remember, use the given info in the context when you identify the consequence--don't babble or go off on a tangent! Be concise!
    • "In reality________, but our test_________."
  • Know how the p-value compares for a one or two sided test (ch. 20/21)
    • For example, if we conduct a one sided test and get a p-value of .033, what would the p-value have been if it were a two sided test?
  • Find sample size given margin of error! (ch. 19)
  • Know how changing alpha affects beta, and thus affects power! (ch. 21)
  • Know how to identify alpha and beta when the rates of false positives and false negatives are given! (ch. 21)
  • Definition of p-value (ch. 20)
  • Know how changing our confidence level affects the width of an interval and margin of error (ch. 19)
  • Know how changing sample size (n) affects the width of the interval and margin of error (ch. 19)
  • Know the meaning of the confidence level! (ch. 19)
Here are some resources you can use to study!
  • Look over your chapter 19 test!
  • Want to practice a hypothesis test? Try this!
    • Page 471: 17, 19, 21 (each of this is a test with the answers in the back of the book!)
  • Try these problems from the unit review on page 513:
    • 5aef, 9c, 27, 29, 37
  • Need practice with types of error? Look at the questions on the worksheet provided in class! Here are the questions/answers so you can check (answers in red).

Chapter 21: Types of Error
  • In attempt to increase the percentage of people wearing seat belts, Massachusetts instituted a “click-it or ticket” policy. Use of safety belts rose to 62% in 2003, with a goal of surpassing 80% by 2005. That year (in 2005), of 134 stopped drivers, 23 were not wearing their seatbelt. Does this provide evidence of meeting the goal? If we have met the goal, Massachusetts will cut back funding on the “click-it or ticket” program.
a.      Define each type of error and a consequence of each.
Type 1: In reality, Massachusetts has not met it's goal of surpassing 80% of people using safety belts, but our test suggests they have met the goal. As a result, Massachusetts will cut funding on the "click it or ticket" program when they should not.

Type 2: In reality, Massachusetts has met its goal, but our test fails to show this. As a result, Mass. will continue to fund the "click it or ticket" program when they should not.

b.      If we use an alpha level of 0.05, what is the associated confidence level?

This is not on the test!

  •     A company is willing to renew its advertising contract with a local radio station only if the station can prove that more than 20% of the residents of the city have heard the ad and recognize the company’s product. The radio station conducts a random phone survey of 400 people. 
b.      Define a Type I error and identify a potential consequence.
Type 1: In reality, 20% of residents have heard the radio station's ad, but our test suggests that more than 20% of residents have heard the ad. As a result, the company will renew its advertising contract when they should not have.

c.       Define a Type 2 error and identify a potential consequence.
Type 2: In reality, more than 20% of the city's residents have heard the ad, but our test fails to show this. As a result, the company will not review the advertising contract with the radio station when they should have.

d.      Which alpha level--.01, .05, or .10—will maximize the power of this test?
.10, because if we increase alpha, this decreases beta, which increases power (remember, power = 1 - beta)

e.      The company proposes the station call 600 people rather than 400. How will this affect the power? Will this make the risk of a Type I/Type II higher or lower? 
If we increase sample size, this decreases the probability of both type 1 and type 2 error (alpha and beta); thus, if beta decreases, power increases
  •        Testing for Alzheimer’s disease can be a long and expensive process, consisting of lengthy tests and medical diagnosis. Recently, a group of researchers devised a 7 minute test to serve as a quick screen for the disease for use in the general population of senior citizens. A patient who tested positive would then go through the more expensive battery of tests and medical diagnosis. The authors reported a false positive rate of 4% and a false negative rate of 8%.

a.      Define a Type I error and identify a potential consequence.
In reality, a person should test negative (does not have Alzheimer's), but our tests shows they test positive (have Alzheimer's). As a result, the person will go through the more expensive battery of tests when they do not need to. 

b.      Define a Type 2 error and identify a potential consequence.
In reality, a person does have Alzheimer's (should test positive), but our test fails to show this. As a result, this person will not go through the additional medical tests when they should have. 

c.       What is the alpha level?
Alpha is the probability of a Type I error; a type 1 error is a false positive; so alpha = .04 or 4%.

d.      Calculate the power of this test? 
Beta is the probability of a Type 2 error; a type 2 error is a false negative, so beta = .08. Power is 1 minus beta, so power = 1 - .08 = .92!




Tuesday, March 22, 2016

Tuesday HW: Counts Double (b/c it's 2'sday....)

Tonight, please complete the following in your textbook:

Page 491: 3, 17, 21, 27

This homework will be checked and scored as double! This is a great opportunity to STUDY for Thursday's test! Our homework has a confidence interval, a hypothesis test, and some types of error stuff--so the more work you put into this homework, the more you're preparing yourself for Thursday!

And even though it's only 4 questions, it's a good amount of work...so I should see lots of math, conditions, and writing! No homework should take up a half page! (unless you want half credit...)

Some hints/tips/comments on the hw...

  • For #3, think about the p-value they must have gotten to conclude the new device is significantly better...
    • If they concluded the new device was better, did they reject or fail to reject the null?
    • Based on this idea, how must have their p-value compared to the alpha level of 0.05?
    • Now, consider this--given what we know, would we have made the same decision at an alpha level of 0.10? 0.01?
  • For #17...types of error!
    • This is all based on Monday/Tuesday notes from chapter 21!
    • This is a great example of what you might see about types of error and power on Thursday!
  • #21...hypothesis test
    • You also need to read #19 for the full context for this problem!
    • For part a, conduct a complete hypothesis test: hypotheses, conditions, math, conclusion
    • Part b is not asking for your conclusion (that's part of a)--so you're not telling me if you'd reject or fail to reject the null. Instead, for part b, you're actually interpreting the p-value itself!
      • What does this probability mean? (look at your definition!)
      • This is likely the most difficult question/concept/topic on the test
  • #27....confidence interval
    • For a, create an interval--conditions, math, interpret the interval
    • Then, for b, use this interval to decide if the coach's claim is correct/plausible!
I know this is more than your usual homework...but if you put in the time and effort to cover ALL of the details mentioned above, you will be well prepared for Thursday! So do it! Let's work hard and bounce back with higher class averages on this test!



Monday, March 21, 2016

Monday HW!

Tonight, please complete the following in your textbook:

Page 492: 11a-d, 13

These are great examples of what you'll see on your test about Type I and Type II errors--define each and identify a consequence of each!

Remember to use the information given in the context when evaluating consequences of the errors! Try not to "go off on a tangent"--stick to the info in the problem!

And CHECK YOUR ANSWERS IN THE BACK OF THE BOOK! 

See you all tomorrow for some more of chapter 21!


Friday, March 18, 2016

Weekend HW!

This weekend you have some IMPORTANT homework--teaching yourself chapter 21!

Please complete the chapter 21 reading questions and vocab quiz provided in class (or below). 

  • The more effort you put into reading this chapter and understanding its content, the better prepared you'll be for next week!
  • We have 3 days of notes this week, then a test on Thursday, so it's important you work hard on these reading questions and really teach yourself this stuff!
  • The chapter 21 vocab quiz will be collected and graded as a quiz on Monday--get an A!
We will also have our chapter 20 vocab quiz to start class on Monday: here's the list!
  • Notice that many of these words are repeated on your ch. 21 vocab this weekend--so that's some forced studying! 
  • Also, some of these are repeated from our chapter 19 quiz!
    • Standard Error (ch. 19)
    • Critical Value (ch. 19)
    • Margin of Error (ch. 19)
    • Confidence Interval (ch. 19)
    • Hypothesis Test (ch. 20) 
    • Null hypothesis (ch. 20)
    • Alternative hypothesis (ch. 20)
    • P-Value (ch. 20)
    • Meaning of __% Confidence (ch. 19)
    • Fail to reject null if p>alpha
    • Reject the null if p

_____________________________________________________________________________

Chapter 21: Reading Questions!
Use your textbook to answer each of the questions below. We only have 3 days to review this stuff, so you have to teach yourself the foundational terms/concepts yourself—via these questions!
1.)    The chapter starts off with an example of a hypothesis test regarding “therapeutic touch.”
a.       First, read the context—page 473-474 (stop when you get to the ESP? bullet)
b.      Now, look at the “step by step” example on the bottom of page 474:
                                                   i.      Record the null and alternative hypotheses for this problem:
                                                 ii.      Read through the conditions.
                                                iii.      Show the math work for this problem—don’t just copy it from the book, write it out as we would: show the z-score with its formula, the Normal model, and p-value. (All of this information is already show, you just have to organize it as we would).
                                               iv.      The p-value for this problem is 0.788. In our null hypothesis, we are assuming this person is not capable of therapeutic touch. Our alternative suggests that  this person is capable of therapeutic touch. Use this wording/context and our “writing template” to write an appropriate conclusion for this test.
2.)    What is a p-value? Record the definition of p-value—highlighted in blue on page 476.
3.)    Below this blue section there is a sentence in italics (on p. 476). Copy this sentence below!
4.)    Record the highlighted blue text on the top half of page 477.
5.)    Now, read the bottom of page 477, “Alpha Levels.” This references alpha levels and statistical significance; record the blue statement on the bottom of p. 477, and the blue section on the top of p. 478.
6.)    Much of this chapter delves deeper into the details about hypothesis testing. However, we are going to introduce two new ideas: type I and type II error!
a.       What is a type one error? (read the bottom of p. 482)
b.      What is/define a type two error.
7.)    An alpha level represents the “cutoff” value we use to decide if we reject the null hypothesis—but it’s also connected to Type I error. How so? Look at one of the blue highlighted pieces on page 483 and state how alpha relates to Type I error.
8.)    What is the power of a test? (blue stuff on page 483 AND on p. 484).
a.       Read the entire section about power on p. 484!
9.)    How do we calculate power? (look at the bullets on p. 487)
10.) What is effect size? (p. 485)
11.) There are two ways to increase the power of a test. These are going to require some reading…Start with the second bullet on p. 487, then read the top of p. 488. Record the two ways to reduce power below. 


Part 2: Chapter 21 Vocab Quiz!                                  Name:____________________________
Use your textbook, notes, and glossaries (ch. 19, 20,21) to complete the vocab quiz below!

1.) Fill in the blank with the appropriate word: When the p-value falls below the alpha level, we say that our test is ____________ at that alpha level.

a. Significance Level       
c. Statistically Significant               
e. Not Statistically Significant     
b. ___% Confident
d. A critical value

2.) Alpha Level/Significance Level
                a. The z* in the margin of error or confidence interval formula
                b. The “cutoff” value that we use to determine if we made a Type 1 or Type 2 error
c. The “cutoff” value that we use to determine if we reject or fail to reject the null hypothesis
d. The level of confidence we have for a given interval
e. The number of standard deviations/standard errors from the mean for a given confidence level

3.) Alpha Level/Significance Level
                a. The probability of a type 2 error
                b. The probability of a type 1 error
                c. The likeliness that we correctly reject a false null hypothesis
                d. The power of a test
                e. The same as the confidence level for a given test

4.) The number of standard errors to move away from the mean of a sampling distribution for a specified confidence level.
a. Sampling Error             
b. Standard Deviation                   
c. Standard Error                             
d. Margin of Error
e. Critical Value

5.) A z or t score; measures the distance from the mean in standard deviations 
     a. Confidence Interval
                b. Standardized Test Statistic
                c. Alpha Level
                d. P-Valud
                e. Confidence Level

6.) The probability of a type 2 error is:
                a. Alpha                b. Beta                  c. Mu                     d. Sigma                                                e. The same as the confidence level

7.) This is our conclusion if the calculated p-value is above the given level of significance:
a. Accept the null hypothesis     
c. Reject the null hypothesis      
e. Prove the null hypothesis is true         
b. Fail to reject the null hypothesis
d. Fail to reject the alternative hypothesis

8.) Type I Error
                a. This is when we mistakenly reject a true alternative hypothesis
                b. This is when we mistakenly fail to reject a true alternative hypothesis
                c. This is when we mistakenly reject a true null hypothesis
                d. This is when we mistakenly fail to reject a false null hypothesis
                e. This is when we mistakenly a true null hypothesis

9.) Type 2 Error
a. This is when we mistakenly reject a true alternative hypothesis
                b. This is when we mistakenly fail to reject a true alternative hypothesis
                c. This is when we mistakenly reject a true null hypothesis
                d. This is when we mistakenly fail to reject a false null hypothesis
                e. This is when we mistakenly fail to reject a true null hypothesis

10.) Power
                a. A test’s ability to correctly accept a true null hypothesis
                b. A test’s ability to correctly prove a true null hypothesis
                c. A test’s ability to correctly fail to reject a true null hypothesis
                d. A test’s ability to correctly reject a false null hypothesis
                e. A test’s ability to correctly fail to reject a false null hypothesis

11.) If we had a p-value of 0.001, we would make this decision (for any of the common alpha levels):
a. Accept the null hypothesis                                      b. Reject the null hypothesis     
c. Prove the null hypothesis is true                          d. Fail to reject the null hypothesis
e. Fail to reject the alternative hypothesis

Thursday, March 17, 2016

Thursday HW

Tonight, please complete the two hypothesis tests provided (on the worksheet) in class (or below).

This is a great overview of how to conduct a full test--just like last night's homework! Put in max effort!

Here are the correct pvalues/zscores for your hw so you can check:
  • For the problem about "obtaining news from the internet" you are going to get a super low p-value! 
    • p-hat is .33 for this problem! (B/c p-hat is from "the report") This is trickily worded.
    • The p-value = 1.459E-13 = .0000000000001459!
    • z-score = 7.391!
  • For the problem about women over 40 scheduling mammograms...
    • p-value = .00002217 (or 2.2175 E -5)
    • z-score = 4.084


Tomorrow we do some chapter 20 practice! We'll have our ch. 20 vocab quiz on Monday, along with 3 multiple choice questions about intervals! (Period A: this was the "pop test" I mentioned in class--so it's Monday with your vocab!)



Wednesday, March 16, 2016

Wednesday HW

Tonight, please complete the following in your textbook: (Period A notice problem 17 is changed to 19)

Page 471: 13, 19

  • For each of these problems you need to conduct a full hypothesis test! All 4 parts!
  • First, write your hypotheses: be sure to use correct notation!
  • Next, check the conditions to be sure a one proportion z-test is appropriate!
  • Now, show your math
    • I would start by entering everything into the one-prop-z-test on your calculator to get the z-score, p-value, and p-hat
    • Then, on your paper, "show the work"
      • Show the formula used to calculate the z score (given on the calc)
      • Sketch a Normal model and shade
      • Record your p-value
  • Finally, write your conclusion: use an alpha level of .05 (5%) for both problems!
    • Remember, if the p-value is below the alpha level, we will reject the null hypothesis
      • Reject the null: there IS evidence of the alternative
    • If the p-value is above the alpha level, we fail to reject the null hypothesis!
      • Fail to reject the null: there IS NOT evidence of the alternative
    • Here is a writing template for your conclusions:
      • Since the p-value of ______ is lower/higher than the ____% significance/alpha level, we will reject/fail to reject the null hypothesis. There is/is not significant evidence to conclude ___(here, interpret the Ha in context—what were we trying to prove?________ based on the given sample. 
Check your answers in the back of the book! We WILL NOT go over these in class tomorrow, so it's on you to check your understanding! (We aren't going over these b/c we'll be doing plenty of these tests in class)

Tuesday, March 15, 2016

2'sDay HW

Tonight, please complete the following:

Page 469: 1, 2, 9, 15 (**These are the problems on the handout I gave you today in class--they're just copied from our book! Use the back of your book (chapter 20) to check your answers!)

Tomorrow we'll continue to work on hypothesis testing and start to discuss our conclusion! See you there!

Monday, March 14, 2016

Monday = Study!

Tonight, get ready! Study hard! Tomorrow we have our test on chapter 19--confidence intervals for proportions!

Here's a breakdown of what's on our test:

  • Create a confidence interval given a context
    • Remember to check conditions!
    • Show the math--show the formula with values substituted, then find the interval on your calculator!
    • Interpret the interval!
  • Know how confidence level affects the ME and width of an interval
  • Know how sample size affects the ME and width of an interval
  • Find sample size (n) given ME
  • Find ME given a confidence interval
  • Find ME given p-hat, n, and a confidence level
  • Determine the value of p-hat given only an interval
  • Use a confidence interval to determine if it supports a claim (check to see if some value falls within our interval or not!)
  • Explain the meaning of ___% confidence--interpret the confidence LEVEL
    • Be careful of mixing up interpreting the level vs. interpreting the interval!
  • Find the confidence level given n, p-hat, and ME (set up an equation and solve for z*, then use this to determine what the confidence level was!)
  • Know the relationship between n and ME...
    • If we increase our sample size by multiplying by 16, ME (and st. dev.) are only divided by 4!
    • If we want to cut ME by 1/3 (divide it by 3), we need a sample size 9 times as large!

Friday, March 11, 2016

Weekend HW

This weekend, please complete the 13 review multiple choice provided in class, or uploaded under our classroom resources link (word doc), or the questions are below (images)!

This is all review, so I fully expect you to do this even if you were absent! There's no "new stuff" on it! You will not earn full credit if you do not have this on Monday!

And I may check this as a homework assignment, or I may collect it and grade it on Monday--depends on how I'm feeling  Monday morning! :) So, put forth your best effort!

You must SHOW WORK (on here, or separate paper) for questions: 3, 5, 6, 11, 12, 13. NO WORK (on these) NO CREDIT!

Lastly, remember that Monday after school we'll have a review session about confidence intervals (to get ready for Tuesday's test)!

Have a great weekend!




Thursday, March 10, 2016

Ch. 19 Vocab Quiz Tomorrow!

STUDY! Our last (ch. 18) vocab quiz was not up to our usual standard of success! Let's do a (much) better job tomorrow!

Here's the chapter 19 vocab list:
  • Critical Value
  • Standard Error
  • Margin of Error
  • 10% Condition
  • Success/Failure Condition (np>10, nq>10)
  • Know which 3 conditions are checked for a one proportion z interval
  • Confidence Interval
  • What does the "one" in one proportion z interval refer to? (one sample!)
  • Meaning of __% confidence
  • Know how ME is affected...
    • If n increases
    • If n decreases
    • If we increase our confidence
    • If we decrease our confidence
  • Population Parameter
  • Sample Statistic
  • Population
  • Sample
Oh, and make sure you do some studying outside! It's going to be beautiful out today!

Wednesday, March 9, 2016

Wednesday HW

I MADE A MISTAKE ON THE QUIZ C ANSWER KEY I GAVE YOU IN #2! Look at my math--find my mistake and correct it on my answer key, then show it to me tomorrow, and you'll get an extra stamp or 2!

Tonight, please complete BOTH AP FR questions (if you didn't finish #3 in class today). 

You MUST also score each response and provide rationale for homework credit. Use the links below for the AP scoring rubric! (You also have this packet from class today).

I'm more interested in your rationale/scoring than anything else, so be serious about this piece! Looking at AP rubrics is one of the best ways we can prepare for our AP exam (May 12th)!

2010 Scoring Rubric: Scroll Down to #3!
  • The answer they provide for part b is confusing to us...use this instead....
    • The solution in the rubric looks a little weird to us…this is really just another way of stating that our sample is less than 1/10 of the population (or 1/20th); in other words, this is another way of checking the 10% condition! So, we can still create the confidence interval because our sample of 50 songs is less than 10% of the entire population of 2,384 songs.



FRIDAY we will start class with our chapter 19 vocab quiz! 

Here's the chapter 19 vocab list:
  • Critical Value
  • Standard Error
  • Margin of Error
  • 10% Condition
  • Success/Failure Condition (np>10, nq>10)
  • Know which 3 conditions are checked for a one proportion z interval
  • Confidence Interval
  • What does the "one" in one proportion z interval refer to? (one sample!)
  • Meaning of __% confidence
  • Know how ME is affected...
    • If n increases
    • If n decreases
    • If we increase our confidence
    • If we decrease our confidence
  • Population Parameter
  • Sample Statistic
  • Population
  • Sample

Tuesday, March 8, 2016

Tuesday HW

Tonight please complete the "Chapter 19 Quiz A and Chapter 19 Quiz C" worksheet provided in class. 

This is an excellent homework assignment to test where you are with confidence intervals! This gives us a good snapshot of what types of questions our ch. 19 quiz will include!

I'm definitely checking! See ya'll tomorrow!

Monday, March 7, 2016

Monday HW!

Tonight, please complete the following in your textbook--including teaching yourself how to find sample size!

Page 446: 7, 11, 29b, 33, 35

  • For 7 and 11, use today's notes about margin of error! (or, check out page 436 about ME)
  • For 29b, remember the "law of diminishing returns..."
    • Remember, because of the square root, if we (for example) increase our sample size by 9 times (n x 9), we will only cut our standard deviation (and thus, margin of error) by a factor of 3
      • In other words, if we multiply the sample size by 9, we divide the standard deviation/margin of error by 3!
    • Use this rule to think about the new sample size you'll need to cut margin error in half! (If we want to divide standard deviation/ME by 2, we have to multiply sample size by...)
  • For 33 and 35, you need to find the sample size given a margin of error and C. Level....
    • Set up your equation: ME = z*(sqrt(pq/n)
    • Substitute values for ME, z*, p-hat and q-hat, then solve for n!
    • (Lots of algebra)
    • Check out the example (Choosing Sample Size) on page 442!
Tomorrow we'll finish our notes on confidence intervals...see you there!

Friday, March 4, 2016

Weekend HW!

Hey! Read this article about being a Statistician!

This weekend, please complete the following in your textbook:

Page 448: 23abc, 29ac, 24abc

  • **If you do not do 24 you will earn a 0 for your homework (do them all)!
  • For each problem you should...
    • Check the conditions
    • Create the interval: BE SURE TO SHOW THE FORMULA (with values substituted), then calculate the interval with your calculator!
    • Interpret your interval
  • This is a very important homework assignment! These problems give us practice with the most essential skills we need for confidence intervals! (both now and moving forward)!

Here's some general info about showing "the formula" and finding z*!



Here's an example of what I need/expect to see for your "math" work--the formula with values substituted with the interval below it (calculated with our graphing calc!)






Thursday, March 3, 2016

Quiz Tomorrow!

Hey! Check out this article (Statistician job profile) from U.S. News for a quick glimpse of how awesome the career of "Statistician" is!

Tomorrow we will start with a short (10 minute) quiz: here's what's on it!
  • Identify the sample (including sample size)
  • Define the population of interest
  • Define the population parameter of interest
  • Identify p-hat, q-hat, and x
  • Check the conditions for a one-proportion z-interval
    • Random sample?
    • sample < 10% of population
    • (n)(p-hat)>10 and (n)(q-hat)>10
    • State "A one proportion z interval is appropriate."

After our quiz we'll get back to the context regarding the % of people who are married or living with their partner, and we'll figure out the formula for a confidence interval! See you there!

So, your only homework tonight is to be ready for the quiz tomorrow! (look over #'s 1,2 on today's stamp/classwork example!)

Tuesday, March 1, 2016

Tuesday/Wednesday HW

Please complete the following in your textbook for Thursday--and I'm definitely checking since we have 2 nights to do this!

Page 446: 5, 9, 13abd, 21ab, 25

  • For #5, for each conclusion, state if it's correct; if not, explain why it's incorrect
  • For #9, use your writing template to interpret the interval (0.2994, 0.4698) (they write the interval as an inequality in this problem)
  • For 13, 21, and 25 use your graphing calculator to find the interval (we'll discuss this math more on Thursday)
    • Look at the yellow boxes on page 440-441 for calculator help!
    • Also, for 13, and 21 you should check the conditions! Although it's not stated in the question, any time we create an interval we should check the conditions!
      • We should also check conditions for 25, but you can skip those. The conditions are met here, I promise.
  • Use the writing template we discussed in class for interpreting your intervals!
This homework gives you a good idea of what you'll see on a quiz! It's a great snapshot of what we'll need to know from chapter 19! (Of course we'll add a little more on Thursday/Friday/Monday!)