Study!

Tonight's homework is to STUDY! We have our chapter 21 vocab quiz tomorrow and then our test (chapters 19, 20, 21) on Wednesday!

Here's the vocab list for tomorrow--we have not covered some of the words--use the glossary in the back of 21 to review them for tomorrow!

1. Statistically Significant (if our p-value is below the alpha level--so we reject the null--we say our test is "statistically significant" at that alpha level)
2. Alpha Level/Significance Level (both as a cutoff value to determine if we reject or fail to reject the null, and know that it's the probability of a Type 1 error)
3. Beta (the probability of a type 2 error)
4. Critical Value
5. Type 1 Error (when the null is true but we mistakenly reject it)
6. Type 2 Error (when the alternative is true but our test fails to show this)
7. Power (the likeliness/probability that a test correctly rejects a false null hypothesis; also, know that power is calculated by 1 - beta)
8. Effect Size (the difference/distance between the assumed value of p--from the null hypothesis--and our sample percent, or p-hat)
9. Standardized Test Statistic
10. What decision do we make for a low p-value, or a p-value < alpha?
11. What decision do we make for a high p-value, or a p-value > alpha?

Check back tomorrow for a breakdown of what's on Wednesday's test!

Stat Seminar Tomorrow!

Tomorrow we have our AP Stat seminar at 9:10 in rooms 189A and 189B (Ms. Barry and Ms. Patla's rooms). Be there! This will count as a test grade (based on effort), but if you're late you'll lose a point!

We do have homework tonight/this weekend, to be check on Monday--it's all practice on Type 1 and Type 2 errors!

Homework: page 491: 11abcd, 13, 17abc, 19abcd.


If you're having trouble, try structuring your sentences (for each type of error) the following way:

"In reality ____(which is true? the null or alternative? describe this in words, in context)____, but our test ___(either suggests the alternative is true, or fails to show the alternative is true.___"

And don't forget....TEST TUESDAY!

Homework...due tomorrow! (Thursday)

Did I seriously not update the blog yesterday? Slacking.

Tonight, please complete the following in your textbook:

Page 491:  3, 7, 9, 21, 27

Here are some other announcements:

• Our AP Stat seminar is mandatory (for sophomores and seniors) and will be held Friday morning, at 9:00. Be early, not late. We will be using Ms. Patla's and Ms. Barry's rooms--the 180's.
• We have a mandatory AP meeting on April 9th, after school. Be there.
• The AP exam is fast approaching...the best thing you can do is PREPARE. Start now. I just uploaded a pretty helpful AP prep site--learnerator. It's under our links on the right, and can be used for any AP class.

See you all tomorrow! Enjoy sleeping late! (except for you Juniors...you all should just dominate the math test tomorrow!)

 

Tomorrow we'll start to discuss types of error (type 1 and type 2 errors) in class. This will be our last topic to cover before Tuesday's test. This will be tomorrow's homework, to be due Monday:

Types of Error (due Monday):

Page 491

¡11, 13, 15, 17, 19

 

QUIZ TOMORROW!

STUDY! Let's keep up the great work!

Tomorrow there are two parts to our quiz:

1. 17 Vocab words; (the list is on the top right of the blog)
2. 1 Hypothesis Test; (make sure you know all 4 steps!)

After the quiz we'll have some problems to work on in class.

Tonight's homework is the two hypothesis tests provided in class. These will not be checked--they are your resource to study. You can find the answer keys below, so use this to prepare yourself for this quiz!

If you'd like to get ahead, tomorrow's homework (due Thursday) is below:
Page 491: 3, 7, 9, 21, 27

And lastly, if you did not hand in the take home quiz today, turn it in tomorrow! A late grade is better than a zero!

TAKE HOME QUIZZZZZZ!!!!!

This weekend, please complete the take home quiz provided in class. It is also uploaded under our classroom resources and entitled, "Chapter 19/20 Take Home Quiz."

Do your best! Use your notes and your textbook! We did an AWESOME job on the chapter 19 take home test...do the same thing here! Keep up the great work! And use your chapter 19 test as a resource as well!

On Monday we'll wrap up chapter 20/start chapter 21.

Until then, enjoy the weekend! Go to the Seussical! And ace the quiz!

The picture below takes an example and shows a confidence interval/hypothesis test side by side. This might be useful for the quiz, and also shows some of the differences in each of these approaches!

This picture shows step 4 for the hypothesis test ( we ran out of room)...

Thursday HW!

More hypothesis testing! Today we did some work discussing alpha levels and writing conclusions....tomorrow we'll wrap up our chapter 20 notes with Mr. Cawley and then we'll have a multiple choice take home quiz this weekend! Yay!

Tonight, please complete the following:

Page 471: 21, 23, 25

Make sure you do all 4 steps of the hypothesis test!
1. Hypotheses
2. Conditions
3. Math
4. Conclusion

For your conclusions, use the following writing template:
Since the p-value of  (p-value) is lower/higher than the (alpha level) % significance level, we will reject/fail to reject the null hypothesis. There is/is not significant evidence to conclude (describe the alternative hypothesis in words, in context) based on the given sample. 

Here's an example based on the "explosives" problem in our homework (quiz C):
Since the p-value of 0.126 is higher than the 20% significance/alpha level, we will fail to reject the null hypothesis. There is not evidence to suggest that the device is effective in detecting explosives, based on this sample. 

More Hypothesis Testing!

Tonight, please complete the following for homework (you know I'm checking):

Page 469: 9,10,17,19

For 9 and 10, your job is to identify any (and all) mistakes you can find in the work provided. For 17 and 19, you have to do a hypothesis test--that means all four steps! So, for 17 and 19...

1. Write your hypotheses
2. Check the conditions--determine if a one-proportion z-test is appropriate.
3. Use your calculator to find the z-score and p-value, and then make sure you show the work for the z-score and provide a shaded picture.
4. Use an alpha level of .05. Use this alpha level to determine if you "reject the null hypothesis" (if pvalue is less than alpha), or if you "fail to reject the null hypothesis" (if pvalue is greater than alpha). 

Enjoy!

Also, you can find the answers to 2 and 16 (from last night's homework) below:

Monday HW!

Hypothesis testing! Woooo!

Tonight, please start our practice with these hypothesis tests...please complete page 469: 1, 2, 15, 16.

Enjoy! See you tomorrow for more hypothesis testing!

TAKE HOME TEST!

A few things to worry about this weekend before we start hypothesis testing on Monday....

This weekend: COMPLETE YOUR TAKE HOME TEST! YOU WILL NOT EARN FULL CREDIT IF IT IS LATE! Get an A! This is another opportunity to boost your test average in class--so work hard, email with questions (before Sunday night), and use all of your resources!

The take home test is also uploaded under our "Classroom Resources" if you need/want an electronic copy.

Other reminders:

1. Chapter 19 Vocab Quiz Monday! Use your notes to study! Here's what you need to know:
1. Standard Error
2. Critical Value
3. Margin of Error
4. What are the conditions for a one-proportion z-interval?
5. What is a confidence interval (used for)?
6. Know why we call this a "one-proportion z-interval."
7. What is the meaning of ___% confidence?
8. Know how the margin of error and width of the interval are affected by changes in n and z* (our confidence level)
2. If you didn't already (and you want to go), bring your Saturday permission slip (for April 5th) on Monday!

Also, the answer key to last night's homework is below (use this as a resource!):

Thursday HW...

Tonight, please complete the "Investigating CI Follow Up" provided in class. If you don't have it, the questions are below.

**For 1 and 2 you need to do all three steps--so, you'll likely need to do the work on a separate piece of paper.**
1. Check the conditions.
2. Show the formula and use the confidence interval.
3. Write an interpretation of your interval.

Then, try to think about the second part...how do changes in the sample size (n) and the critical value (z*) affect the width of our interval?

Enjoy!

Investigating Confidence Intervals: Follow Up

A survey of approximately 4,200 high school students in the Midwest (at a meeting of the American Public Health Association in Denver) showed that 19.8% of students were “hypertexters” and 11.5% were “hypernetworkers.” “Hypertexting” is defined as sending at least 120 messages per school day. While “hypernetworking” is defined as spending at least 3 hours per school day on social networking sites.

1.       Create a 90% confidence interval for the proportion of Midwest high school students who can be categorized as “hypertexters.”

2.       Create a 99% confidence interval to estimate the percent of Midwest high-school students who “hypernetwork.”

3.       Consider the equation for a one proportion z-interval. What two variables do we, as the statisticians conducting  the study, have the ability to manipulate?

____________    and _____________

4.       How will changes in _______ affect the width of the interval?

5.       How will changes in _______ affect the width of the interval? 

Stats HW!

Good work today! Tomorrow we'll continue to explore confidence intervals for proportions!

Tonight, please complete the worksheet provided in class; if you lost it (or were absent), you can find the questions below. Use the hints below for d,e,f--no effort, no credit! I know I haven't taught these (specifically), but I want you to figure them out!

**We did not cover d,e or f today in class. I want you to try to figure these out! Here are some hints**

• For d, you need to calculate margin of error; this is just a matter of using the part of the confidence interval formula that represents "margin of error," and then substituting in the correct values. For more info, look at page 436.
• Use the same confidence level (90%) as for a,b, and c.
• For e and f, you need to find the sample size, given a margin of error. You are not given "p" or "p-hat." In any situation like this, we'll use 0.5 for p and q (hat). This will give us a "conservative estimate of margin of error.
• You can see an example of this type of problem (done out) on page 442. Once you set up the equation, this becomes a margin of error question. 

Homework Questions:

AP Statistics Exam: Estimating Population Proportions

Complete each of the questions in the space provided. Remember to complete each problem thoroughly, checking all conditions and showing your work. Write neatly in the space provided. All conclusions should be written in complete sentences.

1.) A Rutgers University study released in 2002 found that many high-school students cheat on tests. The researchers surveyed a random sample of 4500 high school students nationwide; 74% of them said they had cheated at least once.

a.) Create a 90% confidence interval for the level of cheating among high-school students. Assume the conditions for inference have been satisfied. You may use your graphing calculator to create your confidence interval, but still must show the formula with the appropriate values substituted)

b.) In a complete sentence, interpret your confidence interval from part a.

c.) A teacher surveys his students and finds that 68% of students have cheated on a test. Does this value seem reasonable? Surprising? Explain your reasoning.

d.) Suppose we sample 2,000 students and find that 67% have cheated. Calculate the margin of error.

e.) If we want to have a margin of error of only 3% and want 98% confidence, how large of a sample must be used?

f.) If we want to have a margin of error of 5% to create a 95% confidence interval, what is the appropriate sample size?

Quiz Tomorrow!

Quiz tomorrow! Even if you were absent! The quiz will ask you for the following...

• Define the sample and population (in words)
• Identify p-hat, q-hat, x, and n (remember, x is the number of "successes," or n times p-hat)
• Identify p, the population parameter we are trying to estimate
• Check the conditions (10%, random sample, success/failure) to see if a one-proportion z-interval is appropriate

Tonight, please complete the following for homework (it'll make you study for your quiz!):

Page 448: 21ab, 23abc, 24abc

Enjoy! Go do your homework outside in the warm weather and sun today! It'll be sunny until like midnight! (ish).

Also, one last thing to remember....SATURDAY SESSION PERMISSION SLIPS ARE DUE FRIDAY. 

Mondayyyyyyy...

Back to work! Onto confidence intervals, some of my favorite stuff in AP Stat!

Tonight, please complete the following:

Page 446: 1,3,5,9,10

*For 9,10, the interval is given to you; I want you to use your writing template to interpret the confidence interval, in context
*For 3, check the conditions! (If one condition fails, comment on that one that fails; you don't need to comment on all 3 unless all 3 pass)
*For 5, look back at chapter 19 for help! The book gave 5 statements about the interval for the sea fan and explained why only 1 was correct!

Stats HW!

1. Enjoy your weekend!

2. Please complete the chapter 19 reading quiz provided in class. Remember, this is a quiz grade! Get a 100%! In addition (as part of this quiz grade), please complete the attached table regarding sampling distributions. You have all of this information in your notes (from chapter 18); you just have to organize it all and re-write it into this table! (This will be an additional 3 points on the quiz grade--you either finish, or you don't; 0 points, or 3 points).

The reading questions are below:

Chapter 19 Reading Quiz: Confidence Intervals for Proportions

Read the chapter! You can surely answer these without reading everything; however, the more effort you put into reading about and understanding confidence intervals, the better prepared you’ll be for this week of class!

1.       Write down the interpretation of the confidence interval (complete sentence) created for the proportion of sea fans on the Las Redes Reef that are infected with aspergillosis. Five statements are provided on page 434; your task is to write down the correct interpretation for a confidence interval. (1 point)

2.       What is the name of the interval calculated and interpreted in this chapter? (1 point)

3.       Consider the “Just Checking” question at the bottom of page 434. Which of the five statements (on page 435) is correct? (Provide the number below). (1 point)

4.       What does “95% Confidence” really mean? (page 435-436). Read this section of the chapter and provide the meaning of “95% confidence,” in your own words. (Consider the last 2 sentences of the section!) (1 point)

5.       Define margin of error (ME). (1 point)

6.       Define critical value. Also, what symbol is used to represent a critical value?  (1 point)

7.       We use conditions to determine if certain assumptions are reasonable. Consider the “Independence Assumption” on page 438. What conditions do we check that allow us to assume independence? (List 3 below). (1 point)

8.       There is an additional assumption we make—the “Sample Size Assumption.” What condition do we check to allow us to assume our sample size is large enough? (1 point)

9.       The formula for a one-proportion z-interval is provided at the bottom of page 438. Write this formula below. In addition, include the formula we use to calculate standard error (SE). (1 point)

10.   Consider the “step-by-step” example on page 439. Read the problem and follow through the solution. In the space below, provide a general process for how we build confidence intervals. Do not provide numbers/a solution for the problem; instead, your job is to write a numbered process for how we could approach any confidence interval problem. (2 points)

11.   Read the TI Tips on page 440-441. Write down the sequence of buttons we press to create a 1-proportion z-interval on our graphing calculator. (1 point)

12.   Page 441 starts a “What Can Go Wrong?” section to end the chapter. There are 8 bolded (and italicized) phrases by the red bullets (page 441 and 443). List these 8 phrases in the space below. (1 point)

   If you lost your table, it should look like this! (Fill in the missing info):

  

Ch. 18 Vocab Quiz Tomorrow!

AP EXAM MONEY IS DUE TOMORROW! DON'T FORGET! YOU NEED THE FORM, AND YOU NEED EXACT CHANGE!

Tonight, please complete the following for homework:
Page 429: 23, 25, 27, 35

In addition, study for your chapter 18 vocab quiz tomorrow! Here's some stuff that's on the quiz (other than the vocab list at the back of chapter 18):

• Know the symbols for sample mean/proportion/standard deviation vs. population mean/proportion/standard deviation
• Make sure you know which sampling distribution is used for which type of data (categorical or quantitative)
• I might give you a few questions and ask you which requires a sampling distribution (like the slides today); remember, a sampling distribution question asks about the mean/percent of a sample
• Know what happens to standard deviation (spread) as sample size increases
• Know which conditions apply to which sampling distributions
• Vocab:
• Sampling Distribution
• Sampling Distribution for a Proportion
• Sampling Distribution for a Mean
• Standard Error
• Central Limit Theorem
• Sampling Variability/Sampling Error
• 10% Condition
• Random Sample Condition
• Success/Failure Condition
• Large Enough Sample Condition
• 
  

Sampling Distribution Homework!

Tonight, please use the applets we explored in class to answer each of the 7 questions on the worksheet provided in class. If you lost the questions, they're right here! (And the links for the applets are below as well!)

Exploring Sampling Distributions

1.       Describe/outline the process shown in the applets to define a sampling distribution for sample proportions.  WRITE YOUR ANSWER USING COMPLETE SENTENCES. (2 points)

2.       After exploring the sampling distribution for proportions, define the model—shape, mean and standard deviation. WRITE YOUR ANSWER USING A COMPLETE SENTENCE. (1 point)

3.       Describe/outline the process shown in the applets to define a sampling distribution for sample means. WRITE YOUR ANSWER USING COMPLETE SENTENCES. (2 points)

4.       After exploring the sampling distribution for means, define the model—shape, mean and standard deviation. WRITE YOUR ANSWER USING A COMPLETE SENTENCE. (1 point)

5.       Discuss with your group: what would the sampling distribution for maxima look like? Sketch a distribution and describe the shape (in words). (1 point)

6.       Discuss with your group: what would the sampling distribution for medians look like? Sketch a distribution and describe the shape (in words). (1 point)

7.       Discuss with your group: what would the sampling distribution for minima look like? Sketch a distribution and describe the shape (in words). (1 point)

     Applets: 

      http://onlinestatbook.com/stat_sim/sampling_dist/index.html

      http://www.rossmanchance.com/applets/ 

Tuesday HW...

Tonight, please complete the following:

Tuesday Homework:
Page 428: 5, 7, 9, 11, 13

*If you were absent today we took a bunch of notes on sampling distributions for proportions; ultimately, if you can figure out these homework problems, you know what you need to from today.*

Tomorrow we'll answer some homework questions and then start talking about sampling distributions for means! (Using this applet: http://onlinestatbook.com/stat_sim/sampling_dist/index.htm)

Back to work!

Onto the new unit....sampling distributions! For future reference, the chapter 18 powerpoint is uploaded under our classroom resources...

Work hard on this stuff! The year is going to move more and more quickly over the next few months....make sure you're on top of your game in class, and that you come get help as soon as you need it!

For tonight, please answer questions 1 and 2 on our handout (provided in class) based on the applet below. If you lost the paper, the two questions are below:

Here's the link to the applet:   http://www.rossmanchance.com/applets/         (choose Reese's pieces)

1. Describe/outline the process shown in the applets to define a sampling distribution for sample proportions.  WRITE YOUR ANSWER USING COMPLETE SENTENCES. (2 points)

      2. After exploring the sampling distribution for proportions, define the model—shape, mean and standard deviation. WRITE YOUR ANSWER USING A COMPLETE SENTENCE. (1 point)

     I'd recommend the following sentence for #2: The sampling distribution for proportions is _______ with a mean/center of ________________ and a standard deviation of ___________.

If you'd like to get ahead, tomorrow we'll look at this applet: 

http://onlinestatbook.com/stat_sim/sampling_dist/index.html