Please check your mail frequently. (If you’ve set up forwarding to another address, you still have to log in to your TC3 email at least once a semester or the account will go inactive.)
Contents:
Greetings, statistics buffs!
Your grades have been posted in myTC3/myInfo. If you would like a grade computation, just drop me an email from your TC3 email account.
My thanks to all of you who completed the Course Debriefing. I will read them carefully and use your comments to improve next semester’s course.
Have a great holiday season!
Greetings, statistics buffs!
Just a reminder: if you haven’t turned in your Course Debriefing yet, please bring it with you to the final exam. I’d like to get a 100% response rate.
Thanks, and see you tonight!
Greetings, statistics buffs!
Quiz results were less than I was hoping for: median 9.0, mean 8.7. There are three main problem areas that a number of you need to focus on:
Suggestion: You may not have time for all the Practice Problems for Statistics, but at least write the hypotheses and do the requirements check so that you can practice not making those common errors.
Reminder: There’s no quiz on sections 12.1 and 12.2, but those sections are included in the exam. This Tuesday will be your only opportunity in class to ask questions about them, so definitely do the Chaper 12 homework. You never know, homework might get checked again this week!
If you have an approved Field Project Plan, please attach it to your Field Project writeup. I don’t have a record of whose Plans I approved, so in case of any question about whether you can present your Field Project to the class that’s your insurance. It’s also important if there’s any question about whether you followed the apprpoved plan in your project.
If you don’t have an approved Plan, you should still feel free to ask questions in email. I want to see everyone do the best project you can do.
As announced in class, there is no longer a 10-point penalty on your project grade for not having an approved Plan. However, without an approved Plan you do risk doing a project that is unacceptable, so if you have any questions at all please email me as early as possible.
Greetings, statistics buffs! I hope you all had a happy Thanksgiving Day.
You really need to get your Field Project Plans to me in email ASAP. Your email should contain the answers to the seven questions in the Field Project Plan Web page — just the answers, not the questions. If you're not sure about your idea, you might want to send a preliminary email before answering the seven questions.
I respond to emails within twelve hours, usually sooner. Bear in mind that on class day if you send me an email after lunch I may not see it before I see you in class.
To echo what I said in class, if you wait till next Tuesday’s class to try to get your Field Project Plan approved, you are likely to be disappointed. There will be time during office hours, before class, and in the break to talk with only a few students, so you need to get this done in email.
Why does it matter? First, it’s your protection against doing an unacceptable project and against major problems with an acceptable project. Second, only students with an approved Plan can present their projects to the class on 8 December for a possible 15 points of extra credit.
Greetings, statistics buffs!
As announced in class, next Tuesday’s quiz will cover all of Chapter 10. In addition to studying the homework, you’ll want to work the practice quiz.
Last night’s homework check counts as a quiz, as provided in the Course Outline. If you’re keeping track of your quizzes on the Grade Calculator Worksheet, either write in an extra square or download a new copy from the Web. (I’ve also revised the Excel version.)
Greetings, statistics buffs!
We will not have a quiz in class on Tuesday, but will instead use the time for our in-class M&Ms Lab. Please bring several extra sheets of paper for working the lab.
However, it is still very important to study sections 10.1 through 10.3 and do the assigned homework before coming to class.
Reminder: Many of you need to do better at recognizing the difference between binomial and numeric data. This is critical, because if you get the data type wrong in a problem nothing else can be right.
Greetings, statistics buffs!
Results on this quiz were so-so, not as good as Chapter 7 but better than Chapter 8. Here they are, with Chapters 7 and 8 in parentheses for comparison:
Median: 11.7 (12.7, 9.5)
Mean: 10.9 (12.2, 8.9)
Standard deviation: 2.8 (2.1, 4.1)
Top score: 14.5 (15, 14.4)
On the solutions page, I have corrected an error in the solution to problem 3 and added two common mistakes.
One area where many of you need work is recognizing the difference between binomial and numeric data, and which requirements apply to which data type. Please review that carefully because it will continue to be important through the rest of the course. On every problem, you should always yourself, am I dealing with numerical data or am I just counting yeses and noes?
If you want to know your quiz score before the class meets on 17 November, just drop me an email from your TC3 email account.
Greetings, statistics buffs!
As you know, we do not meet next Tuesday, 10 November. (There will be no office hours that day.) Expect a quiz on Tuesday, 17 November, to cover sections 10.2, 10.3, and 10.1. On the 17th, we’ll cover section 10.4 and do our in-class M&Ms Lab: Inferences for One Population.
I have updated the Chapter 10 Lecture Notes to reflect the actual lecture from last night.
These two weeks are a good time to catch up on material you didn’t understand the first time around. I also recommend that you do the experiment in the ESP Lab, even though you don’t have enough knowledge yet to do the data analysis.
You should also begin thinking about your Field Project. That will be a hypothesis test where you decide what you want to find out about, then go and collect the data.
Greetings, statistics buffs!
Here is the promised follow-up to the question about 95% confidence that “the average American reads ___ to ___ books a year” versus “the average number of books read by Americans per year is ___ to ___.”
I posted the question in an English usage group. Of the dozen or so who responded to the question, most felt that there was no difference between the two, but several felt that talking of “the average American” suggested a typical American, connoting a median rather than a mean.
It’s a gray area, and more responses will doubtless come, but I think a reasonable case has been made that the second statement is less likely to be misunderstood that the first. Someone has earned an extra-credit point, but I can’t remember who. Can the person who first raised the point in last Tuesday’s class drop me an email or remind me this coming Tuesday?
Greetings, statistics buffs!
Please correct a typo in the handout Inferential Statistics Utilities for TI-83/84. On page 4, near the top of the page, look for “Solution”. In the sixth line of that paragraph you’re directed to “Enter E and σ.” That should be “Enter E and s.”
Greetings, statistics buffs!
I just wanted to call your attention to a type of problem we didn’t discuss in class. Instead of asking you about the probability of a sample mean exceeding a certain value, it asks about a sample total exceeding a certain value.
To solve problems like this, remember the rule: “Can I make some change to twist this problem into a problem I know how to solve?” The solution is to convert the sample total into a sample mean, which you know how to do. If not, please look at problem 5 of the practice quiz.
You’ll find an additional practice problem in the Chapter 8 Lecture Notes, just after the note for page 389.
Greetings, statistics buffs!
The three questions on tonight’s survey were asked of 1002 randomly selected America adults in December 2008, according to American Adults Flunk Basic Science (link verified 2009-10-06). As you’ll learn in Chapter 9, a random sample of this size lets you generalize to all American adults with a margin of error of ±3% or less.
Here are the class results compared with American adults:
| Question and Correct Answer* | Answered Correctly | |
|---|---|---|
| Class (N=20) | American Adults | |
| What percent of the earth’s surface is covered by water?
(Answer: 71%; acceptable: 65%–75%) |
50% | 44%–50% |
| How long does it take the earth to go around the sun?
(Answer: 365¼ days approximately; acceptable to me: 365–365.25. I don’t know what was acceptable to the Academy.) |
70% | 50%–56% |
| True or false: There was a time when dinosaurs and humans
lived on the earth at the same time.
(Answer: false) |
75% | 56%–62% |
| (percent who got all three correct) | 35% | 18%–24% |
| *I wrote the questions posed to the class, based on the answers given in the cited article. I can’t be sure that my phrasing didn’t introduce bias, but I think it’s unlikely. | ||
Conclusion: The class came out significantly better than American adults as a whole. The exception was the question about water, where the class percentage was better than the sample but the difference was not statistically significant. Congratulations!
Greetings, statistics buffs!
Effective immediately, office hours will be 5:15–6:15 Tuesdays in room 122 [corrected 2009-10-21 from incorrect “121”]. I’ve updated the online Course Outline.
As always, I encourage you to approach me during the break or after class, and in email.
Greetings, statistics buffs!
Based on what I’m hearing from you and from the Baker Center management, some of you may be expecting more from the tutors than they can deliver. Remember, the primary source of learning is your textbook and the handouts. You should not go to the Baker Center instead of studying them, but after studying them. Ultimately it’s your responsibility to know what’s in your textbook.
For example, if you don’t know how to find the percentile of a data value, you should at least know where your textbook explains it. (Hint: index at the back, and objectives list at the end of each chapter.) You will get better-quality help if you can ask a specific question about a specific passage or problem in the book. It’s not their job to teach you from scratch.
The tutors do the best they can, but they’re not infallible, and they can’t know every detail of every course. Help them to help you by having your textbook open at the place that explains what you need to know. Then they can help you understand what the textbook is saying.
Also, a professional attitude is important. If you’re frustrated because you’re not getting as much time with a tutor as you want, that’s understandable but it doesn’t do any good to get angry and especially not to act angry.
My day job is in customer support, and I know which customers get better help and feel more satisfied with their experience. It’s the customers who have made reasonable effort to solve the problem on their own and who are pleasant and cooperative on the phone. Try to adopt that philosophy when you’re a customer in the Baker Center. Before you ask for help, make sure that you’ve done everything you can on your own. There will always be something in the book or in a handout that explains how to solve a problem. If you’ve studied the material adequately you will be able to find that section, even if you may need some help interpreting it.
Greetings, statistics buffs!
Based on your questions and the papers turned in, there are some common trouble spots in people’s understanding of Chapter 2 and Chapter 3:
Some used an incorrect variant of the page 153 procedure. If you slept 8 hours, and there were several occurrences of “8” in your data, you don’t count any of them in finding your percentile rank. Your percentile rank (page 153) is the number of people who slept less than you, divided by the sample size, times 100%.
You’ll have a chance to show you’ve learned all of these on the final exam. You’ll also need to know data types and percentiles for the work we do in every chapter of inferential statistics.
Greetings, statistics buffs!
Just a reminder: the Shoe-Size Lab is due promptly at 6:30 Tuesday. Remember that it is your responsibility to get it stapled before you bring it to class, because unstapled pages get mixed and lost.
With the Sleep Lab I noticed a number of you did not show you work. Please show your work on the Shoe-Size Lab and all other written work.
See you Tuesday!
The temporary equipment will be there again on Tuesday and possibly the following Tuesday. I tried to get us a different room, but no smart rooms are available, so I'm afraid we’ll just have to work around it till the permanent equipment is fixed.
Greetings, statistics buffs!
Last night’s class did not flow as I had planned, obviously. You might have left without a clear idea of what to study, so let me list the key concepts for you:
All are in your textbook, except as noted. (“a/k/a” means “also known as”.)
I think one problem is that not everyone was adequately prepared. When there is a calculator handout, I depend on you to practice it before class on your own, so that you don’t get lost during class. Please use Your To-Do List every week as a checklist for reviewing after class and preparing for class.
For next week, please work through the club-head example in last night’s handout, page 1 through the top 2/3 of page 8. (For those of you who were out sick and did not get the handout, that’s all of Scatter Plot, Correlation, and Regression on TI-83/84, plus Getting ŷ from Any x in a Regression on TI-83/84/89 up to but not including Method 2.)
Look at the shutter-speed example in that same handout, but you don’t need to enter it in your calculator.
As always, I’ll answer whatever questions I can in email, and the Baker Center tutors are your friends. Remember their live chat!
Greetings, statistics buffs!
In class we don’t always have time to get through the whole chapter, so your reading is important.
For example, Tuesday we didn't talk about the shapes of distributions (page 80), but they are quite important for you to know. The pictures are idealized, but real data will have a more “bumpy” appearance. When you describe the shape of a distribution, if it’s close to one of those forms you use that name; however, some distributions won’t match any of those and we won’t learn names for them.
As always, if you have any questions about your reading feel free to email me.
Greetings, statistics buffs! The Dean of Instruction has asked faculty to share this statement with you:
Public health officials urge those who are able to do so to stay home and follow self-care guidelines or consult by phone with a health care provider in order to limit the exposure of others and conserve medical resources for those with more serious illness.
Please be aware that due to the growing demands on health services in the face of the H1N1 2009 influenza pandemic, the TC3 Student Health Center will not be able to see all students presenting with fever and cough and /or sore throat. Medical excuses relating to flu-like illness will not be issued.
Please refer to the Pandemic H1N1 2009 information provided on the TC3 website and in TC3 publications (student planner, Pandemic Flu brochure) for what to do if you have the flu.
Your health and the health of your classmates are paramount. The “two freebies” policy ensures that your grade won’t suffer from missing a quiz. If a lab is due, and you’ve done it on the computer, you can email it to me. Otherwise email me and we’ll work something out.
Greetings, statistics buffs!
Just a reminder: Your book unfortunately contains errors. Check Corrections to Sullivan’s Fundamentals of Statistics for each chapter so that you aren’t misled.
For instance, some printings of the book have an incorrect answer for question 13. The Corrections page shows the correct answer. Whenever your answer doesn’t match the book’s, it’s a good idea to check the Corrections page.
Greetings, statistics buffs! I hope you’re enjoying your Labor Day weekend.
Just a reminder: Your To-Do List (pink handout) is a handy checklist of all the things you need to do to be well prepared for class and to succeed in the course.
See you Tuesday!
Greetings, statistics buffs!
Several students asked after class about quizzes. I’ll share the answers with everyone:
One thing we didn’t discuss in class is the timing of the quiz. We can either have homework questions (limited to 15 minutes), then new material, then a couple of minutes to review your notes, and then the quiz — or we can have homework questions (15 minutes), the quiz, and then new material. I’ll let the class decide next Tuesday. Be aware that if the quiz comes during class, it is timed and you can’t leave early or get extra time. If we have the quiz at the end of class, you can leave if you finish early, or you can have a few extra minutes (within reason) if you need them.
See you next Tuesday, and remember to ask those questions in email or at the Baker Center!
Please visit http://www.tc3.edu/instruct/sbrown/stat5009c/ for information on the calculator and textbook you will need for MATH200. It will be helpful if you can have both of them by the first class.
Several of the “big box” retailers have sales on calculators at this time of year, so you may be able to save yourself a good chunk of change.
Please feel free to email me with any questions.
Greetings, statistics buffs! I’m looking forward to meeting you.
For those who like to plan ahead, I want to let you know what you’ll need for the class.
Our textbook is Sullivan, Michael, Fundamentals of Statistics (Pearson Prentice Hall, 2008) — Either buy the printed textbook, or if you’re really comfortable reading a whole textbook online you can buy just the Student Access Kit and access course number brown90824 at coursecompass.com. You need one or the other, not both.
The required calculator is any model TI-83 or TI-84. Buy on price; the few additional statistics features in the TI-84 Plus Silver Edition are not significant for our class. Most of the “big box” retailers carry TI-83s or TI-84s, and if you have the option of shopping there you can usually find a bargain. (If you have a TI-89, TI-92, or Voyage 200, please see the Web page Can I Use a TI-89 for Statistics Class?)
Please try to have it for the first class meeting.
Our course Web page is http://www.tc3.edu/instruct/sbrown/stat5009c/ — there you’ll find assignments, quiz solutions, and informational handouts. I’m still making some minor tweaks, but I don’t expect to make any major changes.
If you have any questions about anything, please feel free to email me at Browns@tc3.edu. I usually respond to emails once or twice a day.
See you on Tuesday, 1 September!
home page | problems with viewing?
This page is used in instruction at Tompkins Cortland Community College in Dryden, New York; it’s not an official statement of the College. Please visit www.tc3.edu/instruct/sbrown/ to report errors or ask to copy it.
For updates and new info, go to http://www.tc3.edu/instruct/sbrown/stat5009c/