Homework Assignments for COB 191.7 (1:25 PM class)

Fall 2003

To prepare for class for Wednesday, August 27th, please do the following:

  • Read Chapter 1 in your text.
  • Answer questions 1.34-1.40, and 1.44-1.49 orally.
  • Skim Appendix 1.1 and Appendix 1.2, and if you come to an unfamiliar topic, read the discussion of it carefully. It will be assumed throughout this course that you are familiar with these Windows and Excel fundamentals. Throughout the course, ignore any Minitab work, like Appendix 1.3—Minitab is a different statistical program, and we won’t be using it.)
  • Orally answer questions 1.3, 1.10-1.12, 1.18, 1.22, 1.23, 1.26 and 1.67. (Note: you should be prepared to intelligently discuss any of the “oral” problems in class. This is a general expectation for this class.)
  • Access the 191 page of my website (cob.jmu.edu/stevensp). Familiarize yourself with any additional relevant information that you find on the COB 191 page of the site. There’s a lot of it!

Before class on Friday, August 29th, please do:

  • Read section 2.1. Do problem 2.7. (Note that the datafiles are on your book’s disk, so that you don’t need to enter them by hand.)
  • Read sections 2.2 and 2.3.. Start work in ALEKS. You should aim to reach the first week’s objectives by the end of Sunday. This week is a “milk run” with ALEKS, so you won’t lose points for not reaching the objective. By the end of the second week, though, you’ll need to have completed about 15 ALEKS topics, so you’ll want to get started!

NOTE: You’ll work through ALEKS much faster by taking your time on each question, especially in assessment. ALWAYS look over your answer before submitting it to ALEKS. If you’re given a data set with 18 entries and you make a graph for 17 entries, you know it’s going to be wrong, and ALEKS will make you do a new problem!

I’ve written a number of Excel templates to help you with this work—feel free to use them. In particular, the two topics of histograms and frequency polygons can take a fair amount of ALEKS time. My templates on the website can help you speed this work considerably.

Before class on Monday, September 1st, please do:

  • Read section 2.4. While you should be able to read Pareto diagrams, I will not ask you to create them in Excel.
  • Read section 2.5. We’ll have more to say about contingency tables later, in the online reading.
  • Review Chapter 2. Look through the Chapter Review problems, pick some out at random, and determine which tools from the chapter you would use to address these problems. You need not write anything for this exercise, but it’s a great way to self-assess. If you aren’t sure that you could do one of these review problems, give it a try. If you get stuck, you’ve identified a weakness that we need to address.
  • Read section 3.1. Read section 3.2 up through the discussion of quartiles on page 92.
  • Continue to work on ALEKS. By this time, you should have 7 or 8 completed in your ALEKS “Pie”. While you receive no ALEKS grade for this first week, but Sunday, September 7th, you’ll need about 15 pieces of pie to get full credit for the week (and more is better)! Remember that it’s wise, when possible, to choose topics in ALEKS corresponding to what you’ve just read, or what we’ve done in class.

Before Class on Wednesday, September 3rd, please do:

  • Skip page 93 on the geometric mean. Continue reading section 3.2 up through page 101 (we won’t use Minitab, so you can skip page 102). Note that the functions MEDIAN, AVERAGE, MODE, STDEV, VAR, QUARTILE, MAX and MIN should be of use to you when working problems like this in ALEKS or elsewhere. The advantage of Excel is speed and accuracy; the disadvantage is that you may not know what you’re doing!
  • Read section 3.3. In Excel, note that you’ll be using VARP and STDEVP to get the right answers for population variance and standard deviation. It makes a difference whether you’re dealing with a population or a sample. While you should be able to do these calculations (and those in 3.2) by hand, that’s primarily so you know what these quantities represent. In practice, you’ll almost always use software (like Excel) to compute them.
  • As always, continue working on ALEKS, choosing topics in a way that, as much as possible, matches our classroom discussion and your reading and homework. Remember that you should have about 15 “pieces of pie” by Sunday of this week!

Before Class on Friday, September 5th, please do:

  • Read section 3.4. Read section 3.5. Remember, when ALEKS wants you to do box and whisker plots, that you can use my template in Excel for the (unmodified) box and whisker plot. Be sure you understand all of the calculations that the template is doing, and what each line or end in the box and whisker plot tells you. You should be able to do such problems by hand, if the need arose. (Note that Excel’s QUARTILE calculation may give you a value slightly different from what ALEKS gives. I find ALEKS’ “technique B” for percentiles to be the easiest.
  • Read section 3.6. You may ignore the formula at the bottom of page 120 and the calculations on page 121. Just get a sense of what r is telling you, and what it means for r to be
  • close to 1
  • close to –1
  • close to 0
  • positive, or
  • negative
  • Flip through the problems in the chapter review. You need not do the problems, but be sure you would know how to approach them. If you don’t, review the chapter text again. If you still are at a loss, bring your questions to class.

Before Class on Monday, September 8th, please do:

  • Read pages 6-1 to 6-8 of the text supplement Probabilities and Expected Values which you will find on the website. This reading replaces much of the Chapter 4 material from your text, although both sources cover the same material. Use your textbook as a secondary source when working on this chapter.
  • Answer questions 4.1, 4.6, 4.8abcd and 4.9abcd in the text orally.
  • Catch up with anything from previous weeks that is still causing your problems.
  • As always, keep working on ALEKS. The probability topics are particularly relevant now.

Before Class on Wednesday, September 10th, please do:

  • Read pages 6-9 to 6-14 of the text supplement Probabilities and Expected Values which you will find on the website. The tables described here can make working with conditional and joint probabilities much easier, and pretty much summarize the formulas that you read about for Monday’s class. Work through the example carefully to make sure you see where all of the numbers come from.
  • Continue your work in ALEKS.

Before Class on Friday, September 12th, please do:

  • Read pages 138-140 in your text to lock down the ideas of classical, empirical, and subjective probability. Note that the text uses A’ for the complement of A, while my writeup used ~A. If Venn diagrams are fuzzy to you, review them, too. You’ll be using them in ALEKS.
  • Read pages 143 – 144 in the text on the General Addition Rule.
  • Orally answer question 4.5. Orally answer questions 4.25 and 4.51 through 4.58.
  • Continue working with ALEKS. The week 3 objectives should be done by Sunday at midnight.

Before Class on Monday, September 15th, please do:

  • Review all materials to date in preparation for your exam. The exam will be on Thursday night at 8 PM in Room 1302 of the Health and Human Services building (HHS). (That’s part of the CISAT building that you come to first if you take the bridge that crosses Route 81 from this side of campus toward CISAT.) You are permitted to bring one 3” x 5” card to the exam as a “cheat sheet”, and to write (on both sides of it) anything that you would like.
  • Recall that we’ll have a review session on Tuesday, September 16th at 7 PM in Room 105 of Showker Hall.
  • Continue working in ALEKS.

Before Class on Wednesday, September 17th, please do:

  • Read sections 5-1 to 5-3 in your text.
  • Continue preparing for your exam on Thursday. Note that there are three different files available on my website that contain sample problems and solutions. I especially encourage you to work through last semester’s exam. Look over the course objectives list on the website as well—the test is structured around the objectives in headings 1 through 4.
  • Keep working with ALEKS. The ALEKS topics for this week deal with probability topics that correspond to Chapter 4 of your book. They therefore will give you practice on test-related material.

Before Class on Friday, September 19th, please do:

  • Class is cancelled for this day. Continue to study for your postponed test, which will be given during the upcoming week at a time to be announced.

Before Class on Monday, September 22th, please do:

  • Read Section 5-5 in your text.
  • Do problem 5.29a without using Excel’s =POISSON() function.

Before Class on Wednesday, September 24th, please do:

  • Read Topic T in Demonstrations IV at my website, which discusses how to effectively use Excel’s =BINOMDIST() function. While you’re playing with Excel, figure out how to use the = POISSON() function. To do this, type =POISSON( in any empty cell, then click on the “=” sign that appears to the left of the editing window near the top of the Excel sheet. (It may appear as “fx” on your machine.) Excel will pull up a help window for the Poisson function. You’ll be expected to be competent in the use of both of these function. You are welcome to use these functions in doing your homework with these distributions.
  • Continue working in ALEKS. I strongly advise using Excel’s =BINOMDIST function for the binomial problems. I won’t be asking you to compute these by hand.

Before Class on Friday, September 26th, please do:

  • Problem 5.29a (using Excel’s POISSON function), 5.30bc (again using Excel’s POISSON function), 5.34ab, 5.35.
  • Read problems 42 through 50. When you come to class be prepared to state whether each problem should be approached with the binomial distribution, the Poisson distribution, or neither. This is an important skill.
  • Review Chapter 5.
  • Keep working in ALEKS.

Before Class on Monday, September 29th, please do:

  • Read Section 6.1 in your text. Ignore any discussion of using Table E.2 in the back of the book to compute probabilities from z scores. We’ll use Excel to do this. You should understand the concept of z scores, however.
  • IMPORTANT! On the website, read pages 3 through 12 (topics U and V) in the Demonstrations IV file, which deals with the meaning and usage of the normal distribution, as well as instructions of how to use Excel with the normal distribution. The instructions on how to use Excel can help you answer the distribution questions in this week’s ALEKS assignments, and save you a lot of time.
  • Answer questions 6.38, 6.39, 6.40, and 6.42 orally.
  • Do problem 6.10 in Excel, in a form suitable for submission. (Note that the answers to 6.10 are in the back of the book.) This means that I want you to follow the guidelines given on the next page of this assignment list. While I won’t be collecting this problem from you, later in the semester you will need to submit a project in Excel that follows these guidelines. If you have any problem in following them, come with specific questions on Wednesday.
  • If you’re behind, CATCH UP ON ALEKS! The ALEKS problems for the current topics are an excellent match with the kinds of skills that you should be developing.

Before Class on Wednesday, October 1th, please do:

  • Read Sections 6.3 and 6.4.
  • Orally answer 6.43. Continue to work on ALEKS.
  • Think about how the =NORMSDIST and = NORMSINV functions in Excel compare in purpose to formula 6.8 in your book. (It’s worth the time!)

Before Class on Friday, October 3th, please do:

  • Review all topics read in Chapter 6 and in Demonstrations IV.
  • Need I say it? ALEKS!

Before Class on Monday, October 6th, please do:

  • Be sure that you’ve read all of Demonstrations IV. In particular read Section W with great care. The rest of this semester will be work based on a single idea—the sampling distribution. If you understand it, the rest of the semester will be MUCH easier.

I’ll be honest—it’s an idea that takes a bit of time to get your mind around. Read carefully, and we’ll be talking about it in class on Monday.

Before Class on Wednesday, October 8th, please do:

  • Read Section 7.1 in your textbook.
  • Review pages 13-21 in Demonstrations IV at the website very, very carefully.
  • If you want to learn a bit more, read section 7.3 on the CD ROM that comes with your book. It talks about the small and consistent change that is made to standard deviation calculations when drawing from a finite population. I won’t test you on 7.3.
  • Do problems 7.4. 7.4 can help you to better understand what a sampling distribution is. If you aren’t using Excel to do this week’s problems in ALEKS, then do problem 7.7 in Excel. (Be sure you follow the standard operating procedures on the previous page of this assignment list.)

Before Class on Friday, October 10th, please do:

  • Read Section 7-2. Do problem 7.12, 7.13, and 7.15. (Note that, if you do 7.15 in Excel, then part d can be answered simply by changing one number in your spreadsheet.)
  • If you are AT ALL hazy with section 7.1, work additional problems from that section. 7.10 would be a good choice, for example.
  • Continue working in ALEKS.

Before Class on Monday, October 13th, please do:

  • Read section 8.1 in your text.
  • Read pages 1 – 6 of Demonstrations V very carefully.
  • Your second exam (on Chapter 5, 6, and 7) is coming. Begin to prepare.

Before Class on Wednesday, October 15th, please do:

TBA. (It depends on whether you choose to have your second exam before or after the break.)

NO CLASS ON Friday, October 17th (fall break).

NO CLASS ON Monday, October 20th (day off to make up for first night exam).

Before Class on Monday, October 27th, please do:

  • Read sections 8-2 through 8-3 of your text.
  • Work in ALEKS. If you need more practice, do problems 8.3, 8.7, 8.13 and 8.21.
  • Exam scores on the second exam were appalling. In order to give you a chance to learn what you couldn’t demonstrate on the exam and improve your grade, I am going to return your exam (without answers) on Monday. I will also give you a blank scantron sheet. You will then be able to retake the exam as an open note, open book exam, subject to the conditions below. READ THEM CAREFULLY.
  • You MAY use any published book as a reference as you work. You may also refer to your notes.
  • You MAY NOT communicate in any way whatsoever with anyone else concerning the contents of this test. This includes both communicating information to other people and receiving information from them. To spell it out:
  • All forms of communication—written, oral, etc.—are forbidden.
  • All information—answers, approaches, notes of other students, helpful parts of the book, comparing answers, problem difficulty, etc.—is included in this injunction.
  • All other people—classmates, teachers, relatives, etc.—are covered by this injunction.
  • The sole exception to this is that you may ask me to clarify a question that you find to be unclear or ambiguous.
  • Record your name and section on the scantron sheet provided. Be sure to properly code your PeopleSoft number. Failure to blacken the appropriate numbers for your ID can cost you 10 points on this exam.
  • Below the honor pledge on the exam sheet, write this new pledge.

Sign your name under this pledge. I won’t grade your paper without a signed pledge.

  • This exam is due at the beginning of the class on Wednesday, October 29th. It will not be accepted late.
  • If you submit your take-home exam in accordance with the guidelines above, I will grade it and then average the scores that you obtained on your in-class Exam 2 and your take-home exam. This averaged grade will then be recorded in my grade book as your grade on Exam 2. If you do worse on the take-home than you did on the in-class exam, I will leave your in-class exam grade unchanged.
  • Although I trust that your personal ethics would prevent you from cheating on this exam, I reserve the right to verify that cheating has not taken place by asking you to explain the reasoning behind your answers to me. Obviously, students who has worked by themselves should have little difficulty in explaining how they arrived at their answers.
  • I take the honor code seriously. DO NOT CHEAT on this exam.

Before Class on Wednesday, October 29th, please do:

  • Read section 8-4 in your text.
  • Orally do question 8.60, 8.61, and 8.62 in your text. Be prepared to answer them in class. If you need more practice than ALEKS gives you, do problems 8.22, 8.23, 8.24, 8.27.
  • Turn in your exam retest, if you are doing so. Recall that they are due at the beginning of the class, and will not be accepted late.

Before class on Friday, October 31st, please do:

  • Review Chapter 8 thoroughly. Look over all of the materials relevant to your work in Chapters 7 and 8 and LOCK THEM DOWN.
  • Do problems 8.32, 8.33, 8.44, and 8.49 in your text.

Before class on Monday, November 3, please do:

  • Read sections 9.1 and 9.2 in your text. Read the writeup on hypothesis testing on my website CAREFULLY. Think about what this stuff means, and how it ties in with Chapters 7 and 8. It takes a while to get comfortable with it.
  • Orally answer questions 9.1 to 9.4, 9.6, 9.7, and 9.9 to 9.12. Be prepared to discuss these in class.

Before class on Wednesday, November 5th, please do:

  • Read sections 9.3 and 9.4.
  • If you need more practice than ALEKS gives, do problems 9.18, 9.20, 9.22, and 9.24, 9.32, 9,34, 9,36, and 9.38. (Remember that you can check your answers by using my templates!)

Before class on Friday, November 5th, please do:

  • Read section 9.5.
  • If you need more practice than ALEKS gives you, do problems 9.26, 9.29, 9.42, 9.43abcde, 9.50 and 9.56. (Remember that you can check your answers by using my templates!)

Before class on Monday, November 10th, please do: