Two Homeworks Checked Wednesday!

Both of these homework assignments will be checked on Wednesday, 11/4. 

1.)  page 213: 1, 7, 9

• this will be your first homework grade of the second quarter! So...I'm checking, and it counts as double!
• Although there are only 3 questions, they have a lot of parts...I expect to see complete, thorough answers
• If your homework does not look complete, there aren't answers in complete sentences, and/or it looks like you just quickly copied from the back of the book, you will not receive full credit! (likely a 0)

2.)  Please complete the "Chapter 8 Quiz: The LSRL" worksheet.

• SKIP PART 2 (on the back)! I NEVER TAUGHT IT! (yet...)

• This was the first version of your chapter 8 quiz, so it's a great review of everything you need to know about chapter 8.
• Much of this will re-appear on our unit test (which will be within the next 7 classes), so it's an excellent way to review and study!
• I'll give you an answer key after I check on Wednesday!

Enjoy your day off! I'll see you all on Wednesday for some more outliers and influential points!

Stamps Due Tomorrow!

**If you were absent today you MUST make up the test tomorrow or Monday; if you do not have a study hall or can't stay after Monday, you will make it up Monday in class!**

Your only homework tonight is to get your stamps together--they're due tomorrow!

Stamps due tomorrow!

• Count up your stamps (double check!)
• Staple them together/put them in an envelope/bag, and write the total on the front!
• If the total on your paper does not match your actual total you'll get a 0! Double check!
• Stamps must be turned in by Friday!
• You're literally counting the number of blue ladybug stamps you have! 

Once you're stamps are ready (or if you've already turned them in), enjoy you Thursday without homework!

If you'd like to get a head start, here's your homework for the weekend; this will be your first homework grade of the second quarter! So...I'm checking, and it counts as double!

Page 213: 1, 7, 9

Quiz/Test/Quest Thing Tomorrow!

Here's what's on tomorrow's test? quiz? quest?:

• 10 multiple choice questions
• 6 open ended (writing) questions (provided in bold)
• 3 short answer questions (identifying different points in a scatterplot)

Topics on the Quest:

• Know how correlation is affected by converting data to z scores (standardizing)
• Know how to find the correlation (r) from R^2: remember to check the slope to see if it's + or -
• Use a linear model to make predictions
• Calculate residuals: use a linear model to make a prediction, then find actual - predicted
• Interpret slope!
• Interpret y intercept!
• Interpret R^2!
• Know about correlation: you'll have to choose which (of 5) statement does not have an error (remember that "blunder" question?)
• Estimate correlation looking at a scatterplot (consider direction, then strength, to choose which correlation best matches the scatterplot given)
• Write the equation of the LSRL given a data set (Stat, Calc, LinReg)
• Write the equation of the LSRL given a computer output
• Is a linear model appropriate? Check a scatterplot to see if it's roughly linear and has no outliers, check that a residual plot has no pattern, and that the variables are quantitative
• Describe an association (shape, direction, strength, generally...)
• Interpret residuals

And lastly...Remember, stamps are due this week (by Friday)!

• Count up your stamps (double check!)
• Staple them together/put them in an envelope/bag, and write the total on the front!
• If the total on your paper does not match your actual total you'll get a 0! Double check!
• Stamps must be turned in by Friday!
• You're literally counting the number of blue ladybug stamps you have! 

Ch 8 Vocab Quiz Tomorrow!

Tonight, study! Tomorrow we have our chapter 8 vocab quiz! Then, on Thursday, we have our "quest" on chapters 7 and 8! Study now!

Here's a list of the words for tomorrow's vocab quiz:

• Residual (know what it is when looking at a scatterplot with a line of best fit, and know how it's calculated)
• Slope
• Y Intercept
• R^2 (Coefficient of Determination)
• Actual/Observed Value
• Predicted/Estimated Value
• Underestimate
• Overestimate
• Linear Model/Line of Best Fit (an equation used to make predictions for y values, based on x values)
• Least Squares Regression Line (the line that minimizes the sum of the squared residuals)

Words from Chapter 7 vocab quiz that may repeat:

• Correlation (r)
• Explanatory Variable
• Response Variable
• Describe an Association
• Outlier

And here's the answer key to last night's homework so you can get a head start studying for Thursday!

If you'd like to get a head start, here's what's on Thursday's test? quiz? quest?:

• 10 multiple choice questions
• 6 open ended (writing) questions (provided in bold)
• 3 short answer questions (identifying different points in a scatterplot)

Topics on the Quest:

• Know how correlation is affected by converting data to z scores (standardizing)
• Know how to find the correlation (r) from R^2: remember to check the slope to see if it's + or -
• Use a linear model to make predictions
• Calculate residuals: use a linear model to make a prediction, then find actual - predicted
• Interpret slope!
• Interpret y intercept!
• Interpret R^2!
• Know about correlation: you'll have to choose which (of 5) statement does not have an error (remember that "blunder" question?)
• Estimate correlation looking at a scatterplot (consider direction, then strength, to choose which correlation best matches the scatterplot given)
• Write the equation of the LSRL given a data set (Stat, Calc, LinReg)
• Write the equation of the LSRL given a computer output
• Is a linear model appropriate? Check a scatterplot to see if it's roughly linear and has no outliers, check that a residual plot has no pattern, and that the variables are quantitative
• Describe an association (shape, direction, strength, generally...)
• Interpret residuals

Monday HW

Tonight, please complete the worksheet provided in class (or below).

Homework extra credit? Want to get some extra points for your homework average? Then...

Can you find the mistake I made in one of the questions? (I used the wrong word...

Interpret R^2 for this data on the back of the paper!

Remember, stamps are due this week!

• Count up your stamps (double check!)
• Staple them together/put them in an envelope/bag, and write the total on the front!
• If the total on your paper does not match your actual total you'll get a 0! Double check!
• Stamps must be turned in by Friday!
• You're literally counting the number of blue ladybug stamps you have! 

Also coming up this week:

• Chapter 8 vocab quiz; Wednesday
• Chapter 8 quiz: Thursday
• There will be an outline of what's on this quiz on Thursday

See you all tomorrow! Enjoy your Monday!

What do you mean? (*as the Biebs dances through your head*)

This weekend, please complete the "Religiosity and Teen Birth Rate" worksheet/questions provided in class (or below).

• Remember to add question E: "Interpret Slope" at the bottom of your paper! If you don't add this question, I can't give you full credit for homework! (and I'm def checking!)
• Also, just so you know, this was originally going to be your quiz....so this gives you a good idea of some of the types of questions we can expect on an upcoming quiz/test!
• Remember to sketch the scatterplot and residual plot when determining if a linear model is appropriate!

The homework shouldn't take too long...get it done (well)! Then, enjoy your weekend! See you all on Monday (for the last week of October!).

If you've got some time, check out this video about Simpson's Paradox! If you write down 5 things you learned from this video I'll give you some extra credit stamps on Monday!

Oh yeah, and this... (but remember, don't do anything Justin Bieber would do. He might be better at singing, but you're a better person.) 

Seriously....what do you mean? (Think about that every time you proofread one of you Stats answers).

Thursday HW

Tonight, please complete the residuals worksheet provided in class!

• For the first two data sets, examine a scatterplot and a residual plot to determine if a linear model is appropriate, and then write your response (just like today in class)!

Tomorrow we'll discuss this some more, and then move onto the rest of chapter 8--slope, y intercept, and R^2!

Hump Day Homework

Tonight, please complete the following in your textbook;

Page 189: 3, 15a, 35d

• Remember, to determine if a linear model is appropriate, we need make sure our variables are quantitative; we also want to check a scatterplot to see if it's linear and/or has outliers; and today, we added the most important piece--we need to check a residual plot
• If there is no pattern in the residual plot (or the residual plot shows random scatter), then a linear model IS appropriate
• For 15a, the scatterplot and residual plot and context are provided! Check these!
• Your answer should read as follows (this is practice for a quiz!)
• "A linear model is/is not appropriate because....
• _______ and __________ are/are not quantitative
• The scatterplot is/is not roughly linear.
• There are/are not outliers in the scatterplot
• The residual plot shows random scatter (then a linear model is appropriate), or the residual plot shows a pattern or fan shape (then a linear model is not appropriate)
• For 35d you need to check each of the things listed above (for 15a), but this time you have to create the scatterplot and residual plot yourself, with your calculator
• YOU MUST SKETCH BOTH! (If there are not two sketches on your homework--a scatterplot and a residual plot--you will not receive full credit).
• Look at the yellow box at the top of page 184 for help creating a scatterplot!

See you all tomorrow for a half day and more residuals!

2'sDay HW

Tonight, please complete the following in your textbook:

Page 189: 11a, 13, 35acg

• For 11a, pay attention to what information you're given, and think about what you're trying to find...
• For 13a, think about slope and what you learned in algebra--try to decide what the slope tells us about housing prices (based on) housing size...
• For 13b, substitute! (The equation is on the previous page)--remember, the sizes we "plug in" are for thousands of dollars--so think about what number you should substitute...
• For 13c, think about what we learned today!
• For 35a, use your graphing calculator! (This data should look familiar!)
• For 35c, use your graphing calculator to do "LinReg," then use the a,b values it gives you to write a linear equation!
• For 35g, first use your equation (from c) to find the predicted value...then, use the residual given to try to work backwards and find the actual value!

Good luck! More residuals tomorrow--residual plots, and what best fit means!

Vocab Quiz Tomorrow!

Tonight, study your vocab!

Tomorrow we have our chapter 7 vocab quiz...then, it's on to some new stuff--residuals, the coefficient of determination, and linear regression!

Here are the (chapter 7) words that could end up on tomorrow's quiz:

• Explanatory (or predictor) variable
• Response Variable
• Scatterplot
• Bivariate
• Outlier (in regard to a scatterplot)
• Lurking Variable
• Correlation (r)
• Association
• Positive Correlation/Association
• Negative Correlation/Association
• What three things do we have to comment on when we describe a scatterplot?
• Direction
• Form/Shape
• Strength
• What three things do we have to check to see if it's appropriate to use correlation? (conditions)

Weekend HW

Weekend Homework: 

p. 161: 13, 15, 19, 25, and 35b

• Remember, if you're only given a scatterplot and you don't know r, you can't use the word "correlation"
• If you are given r, you always want to reference it in your description ("....with a correlation of ___.")
• If you are given a data set (like 15 or 19), create a scatterplot with your calculator and sketch it, then describe the association
• Also, any time you are given the data set, you should absolutely calculate and reference the correlation (r)

On Monday we'll do some classwork with this stuff, and then on Tuesday we'll take our chapter 7 quiz before starting chapter 8!

Until then, do your homework (I'm checking!) and have a great weekend!

Thursday and Friday HW

Hey....what do you call an average Halloween?

Your homework for the next two nights will be in the textbook:

Tonight's homework: p. 161: 17, 21, 29, 31

Weekend Homework: p. 161: 13, 15, 19, 25, and 35b

Tomorrow in class we will write some descriptions of associations as a class (this is what you have to do in questions 13, 15, 19), and then we'll be ready to move on to the next chapter!

If you'd like, feel free to get a head start on your weekend homework, but you may not be able to completely do 13/15/19 until after tomorrow's class!

See you all tomorrow! Happy Thursday!

A Hallowmean! (BAHAHAHAHAHAHHAHAHAHAHAHHAHA)

Wed nes day HW!

Tonight, please complete the following in your textbook:

Page 160: 3, 5, 7, 9, 11

Due tomorrow, and I'm checking! (Probably). 

*For the histogram question, your x-axis should be "# of broken pieces." Then, you'll have to use the scatterplot to figure out how many "dots" had each number of broken pieces! (Use the back of the book too!)

Tomorrow in class we'll get back to chapter 7, with the goal of finishing our notes tomorrow and Friday, then some classwork Monday, and then on to chapter 8! See you there!

Tuesday HW

Tonight (or tomorrow), please complete the following in your textbook:

Page 160: 3, 5, 7, 9, 11

**This homework will be checked on Thursday in class!

Period A and period D seniors: no class tomorrow! In period D (juniors) and period E we'll use our half hour to look at some videos (tomorrow), and then on Thursday it's back to "regular" class and chapter 7!

4 Day Weekend!!!!

(TEST GRADES ARE IN!)

First and foremost, ENJOY YOUR 4 DAY WEEKEND! Rest up, relax, hang out with friends/family, and come back ready for a fresh start and a new stat unit! And, of course, don't forget to do your homework--it's a potential quiz grade!

So, this weekend, please be sure to complete the chapter 7 reading quiz provided in class! You can also find it under our classroom resources if you lost yours or were out (or just want to type your answers)!

• Remember, this is "new stuff!" Our new unit will not necessarily overlap the first one, so start out strong with an A! Prepare yourself to do well this unit!
• I know I haven't taught you this stuff--use your resources! "I didn't get it" is not an acceptable answer!
• Use your textbook, watch an AP Stats guy video, or check out some other online resources (linked on the blog or elsewhere) if you need to!

I can't wait to see you all on Tuesday! Have an awesome mini-vacation!

TEST TOMORROW!

Below is an outline of tomorrow's test. At the very bottom of this post you can find the answers to both the multiple choice (from Tues) and open-ended classwork (from Weds) I gave you to practice.

Test Outline: Open Ended and 7 MC:

• Use the Normal model to find percents above/below/between (AP Question)
• Shaded model, z score, normalcdf(lower, upper)
• Use your "storms" problem to study--the questions are less direct, and make you think a little bit more, like (a) on the storms question
• Finding new summary statistics after shifting/rescaling...
• Just like our homework--the SAT/ACT problem or #1 on the open ended practice from today!
• Know which measures (spread or position) are affected by shifting/rescaling
• Use the Normal model to find "cutoff" values given a %
• Shaded Normal model, invnorm(% left, mean, Sx)
• Like 2fghi on the open ended from class today!
• Compare boxplots--draw conclusions, in context, based on comparison (not just comparing SOCS) (AP question)
• Determine if a distribution might be "approximately Normal" based on some summary values...(AP question)
• Create a boxplot, given data
• Remember: labels, title, and fence work!
• Calculate and interpret z-scores (in a sentence)
• MC "The caffeine content..."
• Use z-scores to compare values 
• MC #3
• Reading Ogives
• Find 5 number summary, IQR
• Categorical vs. Quantitative variables (which is which?)
• Know how mean/median relate for different shapes of distributions
• "Appropriate summary statistics"

Answers to Classwork (use these to study)!

MC:

5. Some descriptive statistics....B

3. Lauren is enrolled....C

No #. The caffeine content...C

10. The boxplots above...B

21. Data on homes recently sold....A

No #. Students in a large psychology class...C

OE:

UNIT 1 VOCAB TEST TOMORROW! STUDY AND GET AN A!

This is an outline of exactly what's on your vocab test tomorrow. You will have 30 minutes to complete the vocab test (before some classwork). 

1. Quantitative Variable (Ch. 2)
2. Categorical Variable (Ch. 2)
3. Center (Ch. 4/5)
4. Spread (Ch. 4/5)
5. Mean (Ch. 5)
6. Median (Ch. 5)
7. Range (Ch. 5)
8. Interquartile Range (IQR) (Ch. 5)
9. Standard Deviation (Sx) (Ch. 5)
10. Variance (Ch. 5)
11. Outlier (Ch. 4/5)
12. Q1 (Ch. 5)
13. Q3 (Ch. 5)
14. Percentile (Ch. 5)
15. Stemplot (Ch. 4)
16. Boxplot (Ch. 4)
17. Histogram (Ch. 4)
18. Shifting (Ch. 6)
19. Rescaling (Ch. 6)
20. Z-Score (Ch. 6)
21. Normal Model (Ch. 6)

There is also a short answer section with questions about the following...

• What are the measures of center? (mean, median, mode, midrange)
• What are the measures of spread? (range, standard deviation, variance, IQR)
• What graphical displays are for quantitative data? (stemplot, dotplot, boxplot, histogram, ogive, timeplot)
• What graphical displays are for categorical data? (frequency table, relative frequency table, bar chart, relative bar chart, pie chart)
• Describe shapes of distributions completely (unimodal, bimodal, multimodal, skewed left, skewed right, symmetric, uniform)
• Know how the mean and median compare for different shapes 

If you'd like to get a head start on study for Thursday's test, work through the 7 multiple choice problems provided in class (if you didn't finish)! Here are the answers:

5. Some descriptive statistics....B

3. Lauren is enrolled....C

No #. The caffeine content...C

10. The boxplots above...B

21. Data on homes recently sold....A

No #. Students in a large psychology class...C

Monday HW

Tonight, please complete the following in your textbook: (the questions are typed at the very bottom of this post):

Page 127: 35, 37, 41de

**Period A: I told you the wrong problems on the board! Sorry about that!**

• For 35c, check out the image below!

• For 37c and 41d, (estimate the IQR), this is a multi-step problem...
• First, remember the IQR measures the width of the "middle 50%" of data...
• Use invnorm( to find Q1 and Q3
• This is just like 35c!
• Then, find IQR! (Q3 - Q1)

VOCAB TEST IS WEDNESDAY! (Here's what's on it...use your old quizzes to make some flash cards and study!):

1. Quantitative Variable (Ch. 2)
2. Categorical Variable (Ch. 2)
3. Center (Ch. 4/5)
4. Spread (Ch. 4/5)
5. Mean (Ch. 5)
6. Median (Ch. 5)
7. Range (Ch. 5)
8. Interquartile Range (IQR) (Ch. 5)
9. Standard Deviation (Sx) (Ch. 5)
10. Variance (Ch. 5)
11. Outlier (Ch. 4/5)
12. Q1 (Ch. 5)
13. Q3 (Ch. 5)
14. Percentile (Ch. 5)
15. Stemplot (Ch. 4)
16. Boxplot (Ch. 4)
17. Histogram (Ch. 4)
18. Shifting (Ch. 6)
19. Rescaling (Ch. 6)
20. Z-Score (Ch. 6)
21. Normal Model (Ch. 6)

There is also a short answer section with questions about the following...

• What are the measures of center? (mean, median, mode, midrange)
• What are the measures of spread? (range, standard deviation, variance, IQR)
• What graphical displays are for quantitative data? (stemplot, dotplot, boxplot, histogram, ogive, timeplot)
• What graphical displays are for categorical data? (frequency table, relative frequency table, bar chart, relative bar chart, pie chart)
• Describe shapes of distributions completely (unimodal, bimodal, multimodal, skewed left, skewed right, symmetric, uniform)
• Know how the mean and median compare for different shapes 

Monday's HW Questions:

35.) Based on the model N(1152, 84) for the weights of Angus steers, what are the cutoff values for...
a.) The highest 10% of weights?
b.) The lowest 20% of weights?
c.) The middle 40% of the weights?

37.) Consider the Angus weights model N(1152, 84) one last time.
a.) What weight marks the 40th percentile?
b.) What weight represents the 99th percentile?
c.) What's the IQR of the weights of these Angus steers?

41.) Assume the cholesterol levels of adult American women can be described by a Normal model with a mean of 188 mg/dL and a standard deviation of 24 mg/dL.
d.) Estimate the interquartile range of the cholesterol levels.
e.) Above what value are the highest 15% of women's cholesterol levels?

Weekend HW

This weekend, please complete the following in your textbook:

Page 127: 33, 34, 41abc, 42a

This assignment will give you some more practice finding percentages under the Normal curve! On Monday we'll look at our last type of problem for the unit, working backwards with the Normal model!

Do your homework! I'm checking!

Check the blog post from yesterday for help with normalcdf(!

Lastly, here are the book problems! (For the evens, the answers are in parentheses):

33.) Using N(1152, 84), the Normal model for weights of Angus steers, what percent of steers weigh...
a.) Over 1250 pounds?
b.) Under 1200 pounds?
c.) Between 1000 and 1100 pounds?

34.) Based on the Normal model N(100, 16) describing IQ scores, what percent of people's IQ's would you expect to be...
a.) Over 80? (about 89.4%)
b.) Under 90? (about 26.6%)
c.) Between 112 and 132? (about 20.4%)

41.) Assume the cholesterol levels of adult American women can be described by a Normal model with a mean of 188 mg/dL and a standard deviation of 24 mg/DL.
a.) Draw and label the Normal model.
b.) What % of adult women to you expect to have cholesterol levels over 200 mg/dL?
c.) What % of adult women do you expect to have cholesterol levels between 150 and 170 mg/dL?

42.) A tire manufacturer believes that the treadlife of its snow tires can be described by a Normal model with a mean of 32,000 miles and a standard deviation of 2500 miles.
a.) If you buy a set of these tires, would it be reasonable for you to hope they'll last 40,000 miles? Explain. (No answer for you here...consider how many standard deviations 40,000 miles falls from the mean...is this likely to occur? You can also consider what % of tires will last more than 40,000 miles? Is this likely to occur?)

Thursday HW

Tonight, please complete questions b,c, and d on the "Normal Percentiles" worksheet provided in class (or below). Here are some hints/helpful info for your homework:

• For each problem I need to see (1) a Normal model, shaded, (2) a z-score with work, and (3) normalcdf(____, _____).
• Question (b) is like the SAT example we discussed in class--use those notes as a guide.
• Question (c) is similar to our in-class example, but...
• For (c), we're finding the % above; this means our z-score will represent the "lower bound," and we'll have to use +infinity (a really large #, 9999) as our upper bound
• Question (d) asks you to find the % between two numbers
• For this example, you will have to find 2 z-scores (find the z-score for 4, then for 6).
• In this case, finding a % between, our z-scores represent the upper and lower bound
• In terms of using your calculator, you can use these general formats:
• % Below (Percentile) Questions:
• normalcdf(-99999, z-score) OR 
• For newer calculators: Lower = -9999, Upper = zscore, mu = 0, sigma = 1
• % Above Questions:
• normalcdf(zscore, 99999) OR
• For newer calculators: Lower = zscore, Upper = 99999, mu = 0, sigma = 1
• % Between questions
• normalcdf(lower zscore, upper zscore)
• You can also read through the yellow box (example 2) on page 112-113 for some calculator help

Tomorrow we'll continue to work with the Normal model! On Monday we'll finish our chapter 6 notes, and Tuesday we'll do some practice! Then, Wednesday = unit vocab test and Thursday = test day again!