Tuesday, March 4th

Ch 24 #8, 12, 23, 24

2-t!

Ch. 24 #7 and 9

2 samples, coming at ya!

Friday Article #9 is due!

test ideas

CLT?  Do Ch. 18 #21 and 23
1-mean?  Ch. 23 #21
matched pairs mean? Ch. 25 #14abc is great
Alpha?  Ch. 21 #11
Read?  "What Can Go Wrong?" on p. 415 and pages 444 and 445 (beer!)

t-test Thursday!!

Ch. 25 #14abc

Ch. 18 #24 and 28

matched pairs

Ch. 21 #14

Ch. 23 #24 interval and test

Ch. 25 #7 and 11

t from data

Ch. 23 #23:  test and interval

Class data:  test and interval

t-test

Ch. 23 #8, 9, 12, 22

Mr t, beer and mermaids

Ch. 23 #15

Note:  you'll need to use t* for 60, even though that isn't quite right...

Bonus reminder

Can you calculate sample size?

Here comes a test!

We did a crossword today:  study the vocabulary in chapters 19, 20 and 21.

 

The test:

Multiple Choice (study Ch. 19 #7 & 8 and...?)

A green sheet

Type I and II errors (study Ch. 21 #7 & 8)

Outlier test!!!!

 

Good luck!

alpha

HW:  Ch. 20 #22, Ch. 21 #9 and 10

Good review for Friday's test

HW:  Ch. 19 #26b, Ch. 20 #20, Ch. 21 #6-8

Quest tomorrow!

Ch. 19 #21
Ch. 20 #21

no homework

Quest on Friday
You might want to work on perfecting your homework and getting ready
for your Quest!

got behind, sorry...

Friday:  Ch. 20 #9 and 10

Monday:  Ch. 20 #11 (put a confidence interval and test on one green sheet)

Tuesday:  Ch. 20 #12 (in class) #13 and 14 (just check conditions) #15 & 16 (add a confidence interval on the bottom)

Article #8 + ...

Article #8
statsarticles.blogspot.com
Ch. 19 #4 and 25

More intervals

Ch. 18 #9
Ch. 19 #7, 8, 12, 13cd

Confidence intervals!

HW:  Ch. 19 #13ab (and if you were absent, 14ab also!)

Quiz tomorrow

HW: Ch. 18 #17-19

mean mean mean

Ch. 18 #21-23

Start of Semester 2!!

HW:  Ch. 18 #21ab and 22ab

Extra?

Want a few extra problems to study this weekend?
Here's a few ideas!

Ch. 3 #15
Ch. 5 #23
Ch. 6 #27
Ch. 8 #35
Ch. 11 #11
Ch. 13 #29
Ch. 17 #19, 21a

Unit 3 review answers

4a)  The problem would be that if a group of people who work together all get the same treatment, they might all respond in a similar fashion, because they all might have fun together and then you'll think that that treatment lowered stress when in fact it was the fun they were having together.  Random assignment of treatment will balance out any similarities these people might have with each other and help create homogeneous treatment groups for a more clear view of how the treatment effected the volunteers.

4b)  A control group gives us a baseline for comparison.  Something might happen during the course of the study, say, everyone gets a raise.  Then we could see how the stress level was reduced overall and will be able to tell if the treatment(s) lowered the stress even more.

4c)  No, the study is done on volunteers, not a random sample of the company.  There might be differences from the volunteers compared the average worker.

Unit 2 review answers

1a.  Yes, the residual plot has no pattern.
1b.  233.517 = ABOUT 233.5 more aircraft per year.
1c.  89.9% of the change in aircraft is explained by the regression on year.
1d.  2939.93 + 233.517*(2) = 3406.964 aircraft
1e.  3406.964 + 40 = 3446.964 = 3447 aircraft
1f.  sqrt(0.899) = 0.948 = r = strong, positive, linear relationship between year and # of aircraft
1g. s = 33.43 = sd of the residuals = the LSRL missed the data by an average of 33.43 aircraft
1h.  aircraft-hat = 2939.93 + 233.517*year
1i.  Yes!  In 1990 (year zero) we PREDICT that there were 2939.93 aircraft.

Change!

For Ch. 17 #11 I recommend you ONLY do (a)!

end of the semester

Due Wed:  Unit I review + Ch. 17 #1, 11, 16
Due Thur:  Unit III review

Unit I review answers

1.  The center is at 2.1 hurricanes.  The spread is an IQR of 3 ( 4 - 1), with a range of 7 (7 - 0).  The shape is skewed right.

2a.  increase;  b.  same;  c.  inc.;  d.  same;  e.  inc.

3a.  Since the data is skewed right (draw a little box-plot using the 5 # summary to see this clearly), the mean will be greater than the median.  It is pulled up by the skewness.

3b.  IQR = 3.3 - 2.8 = 0.5
1.5*IQR = 1.5*0.5 = 0.75
2.8 - 0.75 = 2.05 is the lower outlier fence
3.3 + 0.75 = 4.05 is the upper outlier fence

SO:  4.2 is a high outlier and the other two fish are not outliers.

Chapter 6 #25 is odd!  Check is carefully!  Here's a little work:
25b)  z = 0.5;  0.5 is the lower bound and 999 is upper
25c)  lower bound = z = -1.583 and upper bound = z = -0.75
25d)  invnorm(0.25) = - 0.674 = z;  invnorm(0.75) = z = 0.674;  then do algebra to find Q1 and Q3;  IQR = Q3 - Q1

1.  Who = 200 adults
What:  education level and smoking habits
When:  ??
Where:  mall
How:  ??
Why: ??

2.  two categorical variables:  education level and smoking status

3a.  32/200 = 16%;  b.  32/93 = 34.4%;  c.  32/50 = 64%

4.  2 bars:  one for smokers and one for non.  The bars should both add to 100%.  The HS part of smoker bar should be 64%, whereas the 4+ non should be the biggest (48%).

5.  These data provide evidence of an association between smoking and education level.  64% of smokers had only a hs diploma, whereas 40.7% of non-smokers had only a hs diploma.

6.  We have no idea if the behavior changes over time.  This data was only taken at one point in time.

Binomial

Ch. 17 #7, 14
Review worksheet, Unit 2

Answer to basketball simulation

If I set up my simulation like this:

01-72 = makes shot
73-00 = misses

here's some digits:

5730 3485 3246 75 4563
2pts 1pt 2pts 0pts 2pts.

For the 5 runs above my average would be: (2 + 1 + 2 + 0 + 2)/5 = 1.4

That's the simulation.

Now for the expected value

P(0) = 0.28 (misses first shot and is done)
P(1) = (.72)*(.28) (makes the first, misses the second)
P(2) = (.72)^2 (makes both)

Now just run the expected value formula with 0, 1, 2 and the 3 probabilities.

Answers, comments and hints to the review

3a) Note that the problem says that the tickets are bought at the same time for the same price. This makes the formula 3C + 5F.

If the each ticket was bought separately, that would make the formula C + C + C + F + F + ... The mean is the same for either formula. But if the second formula was used, you'd have to do the Pythagorean formula thing.

3b) First do 3C = 450 and 5F = 500; then do sqrt(450^2 + 500^2)

3c) This is only about ONE of each tix: C - F. You can take it from there...

6) Make a 2-way table: 51% in the upper left corner. The other two numbers go on the outside.

a) only 3% is left in the lower right corner
b) P(left|right) = 51/82 = 62.2%. Since P(left) = 66%, this is fairly different, so they are not independent.

7a) 1 - (89/90)^10
7b) 1 - (9/10)^10
7c) 1 - (89/90)^5*(9/10)^5

25d) (0.93)^4*(0.07)

28a) mean = 4

28b) sd = 3.2

28c) Think and read carefully! If the first is bigger than the second then:

(first - second) > zero

So we want to use the mean and sd from above to compare to zero:
z = (0 - 4)/3.2 = -1.249
P(z>-1.249) = (using normalcdf) = 89.4%

42a) 1/100 = 0.01

42b) (.99)(.99)(.01) = 0.009801

42c) (.99)^100 = 0.366

42d) You want to be first!


42e) It doesn't matter! Everyone has a 1% chance!

Now if you're thinking carefully about (e), you might be thinking: "Hey, don't the probabilities change?" Watch this!

Prob(3rd person wins) = (99/100)*(98/99)*(1/98) = 1% (notice how all the fractions reduce!)
Pretty cool, huh?

I will check e-mail at about 10-ish tonight. If you are feeling frustrated, drop a line to:

mrmathman @ gmail.com
I will reply tonight.

Good luck!

Review Answers

It is 8:20pm and I'm starting to put up some answers. Here they come...

THE LAST ASSIGNMENT OF 07!!!

Unit IV Review #3, 6, 7, 23, 25, 28, 42
Ch. 11 #15:  Run 10 times and find the expected value of this problem in theory.

07 is finishing...

Friday:  Ch. 8 #25, 35;  Ch. 10 #1
Monday:  Ch. 11 #2, 5, 19

Review

Wednesday:  we did a 2-page green worksheet that is an excellent probability review.
Thursday:  Unit I review; Page 106 #8, 15, 16, 30

Rules!

Ch. 16 #24, 28

Answers:
24a)  60, 12
b) 6, 1.5
c) 92, 12.37
d) 68, 12.37
e) X + X = 160, 16.97

28a) 10
b) 2.68
c) The seed packets need to be independent of each other.  If they all came from the same batch, they might not be independent.

The end of Unit 07

No homework tonight.

Review

Unit IV Review #1, 5a, 15ab, 16ac, 35-37

Even Answers:
16a) 38.9%
16c) 79.3%

36a) 59.29%
36b) 40.71%
36c) 5.29%
36d) 0.25%

Thursday

Article #7

More Expected Value

Ch. 16 #3, 5, 21
Scramble #2

Expected Value

Ch. 16 #16, 17

Quiz day

Scramble #1 for homework

Answers to Friday's work

Chapter 14 #12a)
1. 0.45
2. 0.87

Chapter 14 #12b)
1. (0.55)^2 = 0.3025
2. (0.45)^2 = 0.2025
3. 1 - (0.87)^2 = 0.2431

Chapter 15 #8
a) P(male | cat) = 6/18 = 0.333
b) P(cat | female) = 12/28 = 0.429
c) P(female | dog) = 16/24

Chapter 15 #10
a) 0.62
b) 0.26/0.30 = 0.867
c) 0.12/0.62 = 0.194
d) 0.66

Chapter 15 #24
No! P(death penalty) = 62%, but P(dp | rep) = 26/30 = 86.7% and P(dp
| dem) = 12/36 = 33%, so party is clearly NOT independent of party!

Quiz on Monday!!!

Answers to Thursday's work

Ch. 15 #4:
a) 0.14
b) 0.23
c) 0.77

Ch. 15 #20
a) P(Canada | Mexico) = 0.04/0.09 = 0.444

b) No, 4% have been to both

c) No, P(Canada) = 18%, which does not equal part (a), above, so not
independent.

Friday HW

Ch. 14 #12, 21
Ch. 15 #8, 10, 15, 24

Start of 15

Ch. 15 #2, 4, 20

Chapter 15

We started chapter 15, but no homework yet.
Get those app's done tonight!!!

Tuesday HW

Ch. 3 #14
Ch. 14 #19, 20, 24, 25

Back from break!

Page 110 #24
Ch. 14 #11 and 14

The last 4 days before Thanksgiving

Tuesday:  Unit 3 Review, #23, 24, 29;  Article #6

Wednesday:  Crossword and flipbook

Thursday:  Test on Unit 3 (1 page multiple choice + normal, 2 experiments, 1 survey)

Friday:  Bias project: poster and presentation

down the river

We started a stratifying activity today. Make sure you find all four
means. We'll wrap it up tomorrow.

HW: Ch. 13 #9-15, 32, 34, 36; Ch. 12 #7, 9--Due Friday!

More design

HW: Ch. 13 #3-5, 28-30

More experiments

Read about observational studies: pages 246-247
Do: Ch. 13 #1, 2, 6, 26

See you Monday!

Work for Thursday night and Friday:
Ch. 13 #19-24

Article #5

Article #5 is due Thursday

Monday Homework

Ch. 12 #15, 16, 23, 24

Here are some of the class notes:

Calling on students for chance cards.

Simple Random Sample:
Use the Random Integer command on my calculator to randomly pick who to call on.
OR:
Put everyone's name in a hat and draw 5 names.

Stratified Random Sample:
I might stratify by class grades. Divide the class into five groups
(A, B, C, D, F) and randomly pick some students to participate from
each group. I think students with high grades are more likely to
participate and vice versa, so this will give me a good
representation.

Cluster sample:
Randomly pick one of the 8 table groups and call on everyone in that group.

Systematic Random Sample:
Use the roll sheet and pick every 5th person.
OR:
Pick every 3rd person as you arrive to class.

Population: Rancho Students
Question: Is RCHS a quality school?
Possible Strata?

Stratifying by GPA:
I would divide the student body into 3 groups: high, med and low GPA.
I would then randomly choose some students to survey from each group.
I think that each of these groups will have very different opinions
about RCHS and I want to make sure that each group is represented.

More chapter 12...

#8, 10, 12, 14

HOW do you collect that data?

Ch. 12 #2, 4, 6

Test tomorrow!

Test on regression tomorrow:

Study chapters 7 through 10 and normal problems
Study your worksheet from Chapter 10
Study your old regression test on temp/crawling
Study Ch. 9 #1
Study extrapolation, outliers and influential points and the standard
deviation of the residuals
Chapter 10 #1 and 2

End of regression, really!

Page 204 #2, 4 and for #28 please interpret s in context.

2 days

Thursday we did a worksheet and Article #4
Friday: Page 207 #17, 37, 40

Onward in 10

We did Chapter 9 #1 in class, and so should you.
HW: Ch. 10 #1, 2, 7

Starting Chapter 10

1978—63,042
1979—226,260
1980—907,075
1981—2,826,095
Year vs. acres devastated by the gypsy moth.
Predict for 1982, please!

Also, MC packet #6

Influential?

Wandering point worksheet
Ch. 9 #11-16
Article #4 due Friday--just write a half-page summary

Review Answers

Well, you lazy bums. I suppose you're too busy on MySpace to e-mail me any answers, so here's a few:

17c) First take the squareroot of 0.924. I forget exactly what this is, but it is 0.9something. This tells us there is a strong, positive, linear relationship between tar and nicotine.

17d) For every 1 more mg of tar, we predict about 0.065 more mg of nicotine.

17e) Even with no tar, we still predict about 0.154 mg of nicotine.

1d) 92.3% of the variation in age can be explained by the regression on age.

1f) She is shorter than predicted, for her age.

1g) Wait until next week.

See you in the morning!
Now go to bed! :o)

Before the test

Finish the crossword and finish your flipbook.

Practice Test

Ch. 8 #10, 32, 36
Add to #10 the interpretation of the y-intercept
Parts of this assignment will graded tomorrow
and this grade will be part of your test grade.

End of chapter 8

HW: Ch. 8 #8abc, 21, 23, 25d

Thursdays HW

Ch. 8:
#25ef, 29c
#30: slope, y-intercept, r, R2, and prediction for 2002
Article #3!!!

No homework for Friday

R^2

HW Ch. 8:
#25bg, 29abd
For #29 find the residual for (250, 95).
Is this data point above or below the LSRL?

Chapter 8

HW: 
Ch. 8 #25ac + find the residual (19, 410)
Ch. 8 #28acd

Scatterplots

HW: Ch. 7 #4, 6, 8
If you didn't get c, d and e right on the test, you need to also do:
Ch. 6 #28

Test tomorrow!

Here is a nice answer from the practice test from chapter 3 about smoking and education level:

The data suggest that a higher percentage of non-smokers continue their education beyond High School than smokers.
Non-smokers have a higher percentage of 4-year college attendees (48%) than smokers (26%). Less of non-smokers have only High School educations (40%) than smokers (64%). Therefore, smoking habits are associated with education level and these variables are NOT independent.


Here is my answer from the CUSS'ing quiz about Halloween candy:

Note to self: since one data set is skewed, I will use the median and IQR:

The boys collected more candy than girls with a median of 62 compared to 45.5.
The boys were skewed left whereas the girls are fairly symmetrical.
(note: no comparison word really needed)
The boys have slightly more spread than the girls. The boys have an
IQR of 31 and a range of 65, while the girls have an IQR of 25 and a
range of 60.

Homecoming

Today in class we made a Flip-chart.

If you finish the review by Monday and give me a chance card.

Review assignment starting on page 105

UNIT  I Review problems
# 5, 21(outlier test on c!),
#25-27, 29(a-g + make a box-plot),
#31, 32  
Double stamped:  
once Friday (for starting)
once Tuesday (when you should be DONE)
            Or by Monday for a Chance Card!

ALSO:  Article #2 due Friday
http://www.mrderksen.com/art2.htm

The end of Unit I

Ch. 6: Finish #25, 26, 27

Are you normal?

HW: Ch. 6 #25ab, 26ab

A nice answer from the quiz

Note to self: since one data set is skewed, I will use the median and IQR:

The boys collected more candy than girls with a median of 62 compared to 45.5.

The boys were skewed left whereas the girls are fairly symmetrical.
(note: no comparison word really needed)

The boys have slightly more spread than the girls. The boys have an
IQR of 31 and a range of 65, while the girls have an IQR of 25 and a
range of 60.

Starting Chapter 6

We started chapter 6.
We will finish it on Wednesday, so hang on tight.
Test on chapters 1-6 next Wednesday.
Don't forget Article #2 is due Friday.

Classwork: Ch. 6 #5, 6, 11
HW:
Ch. 6 #7 and 15
Ch. 5 #30 (you have the ogive on your handout to write on)

Ogives!

Today we did a worksheet on ogives. You can/should do #29 in Chapter
5 to see what you missed.

It looks like our schedule for next week is this:
Mon-Wed: Work very hard and focused and do Chapter 6
Thur-Fri: Review
Mon: Review
Tues or Wed: Test on Unit 1: Chapters 1-6

Last homework for the week

Ch. 5 #5b, 6, 22

Fun web site o' the day:
http://www.stat.tamu.edu/~west/ph/stddev.html

Put that calculator to work!

HW: Ch. 5 #5a, 14, 21, 26, 36, 41

Website from today:
http://www.mathsnet.net/asa2/modules/shodor/plop/

Outlier Rule

HW: Parent Signature and Ch. 5 #23b

Here comes chapter 5

HW: Ch. 2 #8; Ch. 5 #23cd, #35b + boxplot

Tutoring this week: Wed and Thur, 2:30 - 3:15

Last Friday we discussed Ch. 4 #14. We COMPARED the shape, centers
and spreads of the two distributions.

Most Important Stuff in Chapter 4

In class we made a histogram and a calculator for #18
HW: Ch. 4 #8, 12, 17, 24 + Article #1 summary from the web

No Homework

No HW.
In class we learned how use Stat Edit (page 11) and Stat Plot (page
43) and we did this with the hair length data from each class.

Week 2!

In class we took notes from the Workshop Stats Book.

HW: Ch. 4 #3,5; Read your syllabus and Chapter 1
Quiz on Tuesday on syllabus and chapter 1

Friday, Aug. 30th

We did a worksheet in class that was a practice test for Chapters 2 & 3.

Chapter 3, Day 2

Today in class we discussed independence. We analyzed some of our
class data and we did #21.

Homework: Ch. 3 #15, 16, 18
Die is due on Tuesday
Syllabus and chapter 1 quiz on Wednesday

Chapter 3 begins

Homework:
Ch. 2 #7
Ch. 3 #6 & 8

Day 2!

Today we read the information on Page 8 and did problems 2 and 3 in Chapter 2.

HW: Chapter 2 #4-6

Monday, August 27th

First Day of School:

Due tomorrow: One dot-plot of the M&M data (pick any color or the
total) and 2 sentences describing your dotplot.

Due the Tuesday after Labor Day: 1 homemade die. The cube must be
homemade. 4 pts. for durability, 4 pts. for artistic/creativity, 4
pts. for punctuality.

Stuff to consider: Bring in Kleenex, start bringing your calculator,
read your syllabus.

Thanks for a great first day!

Summer "Homework"

If you're reading this you're either bored or you're a conscientious student who wanted to make sure you aren't skipping something important or you're a major procrastinator who is reading this on August 26th. In any case, I asked to do to two simple things this summer:

1) Make sure you have a graphing calculator for fall

and

2) Think about how ridiculous the weather man is: he tells you what the average high temperature is for today and then he tells you today's high, but he doesn't really tell you whether today is unusual or not. How would you know? How could you tell someone whether today is unusually hot or cold?

Project instructions

II. Data Report (20 points)
Due Wed, May 30
This section should be a thorough explanation of how you collected your data and be a beautiful example of how much you've learned this year about the difficulties getting a representative sample.  Examples of what you should include are:

• How you collected your data
• Why you are confident your sample matches your population
• Biases avoided and not avoided
• A copy of any survey that was filled out
• Your data:  either in "Excel" format or in a table/matrix summary.  You need at least 75 people/subjects for each group you want to compare.  Your data should be broken up by any category you want to compare.

III. Exploring the Data (25 points)
Due Fri, June 1

• This section should be an outstanding example of exploratory data analysis (the first unit in our text).  Graphs should show the comparisons between all relevant groups you are comparing.  You should state any preliminary conclusions that can be drawn by using your eyeballs.
• Graphs of your data
• Statistics from your data
• Descriptions of the graphs and statistics.

IV. Analyzing the Data (25 points)
Due Fri, June 1
Analyze your data using whatever method(s) is appropriate for your data.  Your conclusion should be nicely written using all appropriate statistical support.  Remember that confidence intervals can be a powerful method for comparing different groups.

• Hypothesis Test (with conditions checked) and/or
• Confidence Intervals (with conditions checked) and/or
• Regression
• Your Grand Conclusion!

V. Presentation (20 points)
2nd and 5th: Tuesday, June 12th
4th:  Friday, June 1st
Must include:

• Clearly communicate your question and how you collected your data. (5 pts.)
• Visually communication of some sort—you choose the method. (5pts.)
• Clearly communicate your conclusion (5 pts.).
• Be interesting to listen to and give us some sort of "hook" to inspire us to listen (5 pts).
• Do not read off your visual aid—use note cards or your report.  Be careful how you communicate numbers to the class—too many numbers at once is confusing, as is too many decimal places.

VI. Success!? (15 points)
I will evaluate the overall success and difficulty of your project.  More challenging data collection issues add to your score.  Small sample sizes or an overly simple question will lower your score.

Details You Should Know

• Tardies during the project will cost you points.
• NO NO NO NO NO late work is accepted without penalty—even with excused absences.  No late presentations will be scheduled
• Make your own copies anything you turn in.  Once you turn in one part of your report, I need to keep it.
• Don't get lazy—this is to be the summation of what you've learned all year.  
• Please type your paper.  Hand-done work is acceptable for some graphs, etc if it is done very neatly.

Choosing a test

Do this!!!

http://www.ltcconline.net/greenl/java/Statistics/StatsMatch/StatsMatch.htm

Note: the wording on this website is more vague than the AP test. The AP test always asks for "a 95% confidence interval" if it wants an interval (or some other %). Also, the AP problems are longer, and thus have more information that will guide you to deciding what to do.

However, I think that after you 10 or so of these, you'll get used to the wording of this site and it will be good practice. If it is just always frustrating, switch to finding the tests and intervals in your notebook. Every released test (A, B, C,...) has at least one.

Note: this website includes prediction intervals, which you do not
need to know.

Friday

See you this afternoon!

CW: Inverse Normal: '97 MC #12, '02 MC #10
Experiment vs Randomization: G-3a, M-3a, I-4a

Thursday

H-2

Wednesday

No official homework tonight. I trust you're motivated to do some
studying on your own. The link below this post would make for some
great practice tonight.

Choosing a test

Here is a website you can use to practice choosing which procedure to
use for a given problem:

http://www.ltcconline.net/greenl/java/Statistics/StatsMatch/StatsMatch.htm

Note: this website includes prediction intervals, which you do not
need to know.

Tuesday

Pick 3 of the previous night's HW and do them (green sheets)
Also do: MC '97 #2, 5, 6, 16, 29