Instructor’s Manual and Test Bank
For
Basic Statistical Analysis
Ninth Edition
Richard C. Sprinthall
American International College
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Introduction This Instructional Aid has been prepared to accompany Sprinthall’s “Basic Statistical Analysis”, ninth edition, and was written by Richard C. Sprinthall. The purpose of this manual is to aid the busy instructor. Large student enrollments, students with varying educational backgrounds, and a course that students often approach with trepidation….all combine to present the instructor in elementary statistics with a most difficult job. In fact, there is probably no other college course which is more demanding of the instructor's time than elementary statistics. Your students need time and attention, office-hour visits, extra sessions, and perhaps most of all, lots of problems to work out and immediate feedback. This all takes time, and in many cases, the instructor who has perhaps three (or more) other courses to prepare, simply doesn't have enough of that precious commodity ... time. Hopefully~ this manual will help ease some of the instructor's burden. Each chapter is divided into four parts. Part A involves suggestions for classroom activities. I certainly do not presume to tell any instructor how to teach this course, especially since most of you have had years of experience, not only in teaching statistics but also specifically teaching from previous editions of this text. There may some of you, however, who haven't taught the course before and these suggestions may help your preparations for class and hopefully provide a few ideas for keeping the class involved and interested. Too many students look forward to this course as though it were akin to a public flogging, but once you get them into it, once they recognize that these concepts have practical value in their lives, the course should then take on a higher interest level. There will always be some students who claim to have math blocks, and are even willing to proudly proclaim their innumeracy. These may be the same students who would never admit to even a smidgen of illiteracy, but somehow take perverse pride in their lack of numerical sophistication. "I may be innumerate, but I'm not illiterate". This is the same student who will fret over some technical grammatical point, but won't know how to find a percentage. One brief suggestion is to ask these students to clip out and bring to class newspaper or magazine articles that are devoted to proving some statistical or research point. Once they learn to become research critics, they may start carrying their calculators with a new sense of self esteem, and may even look forward to their visits to the computer lab. They may also discover that all newspaper accounts, even of the same story, aren't covered with the same attention to detail. In one analysis of how scientific stories are covered by the press, Evans et al. compared those in the New York Times and Philadelphia Inquirer on the one hand, with those in the National Enquirer or Star on the other (Evans et aI, 2009). The Times and Inquirer offered significantly more details than did the tabloids, but, alas, even the prestige newspapers omitted relevant information in the majority of their reports. We all know that feedback and constant practice are the essential ingredients for student success. The student who puts things off, and "lets it get away", may find it impossible to later catch up. Unlike a history course, where the student can spend an entire weekend ii
doing catch-up reading, the student in statistics needs daily involvement. And daily student involvement translates into more work for the instructor, making up problems, doing the problems, and correcting the problems. The manual contains over 2000 test items, over 1200 multiple-choice items, over 400 true-false items and well over 400 problems requiring calculated solutions. Except for Chapters 1 and 11, which do not demand any numerical calculations, each chapter has a large number of problems where actual values are supplied. These may be used as homework problems, or as exam items. Further, both the multiple-choice and true-false items are odd-even balanced throughout each chapter. If the even-numbered items are used for the main exam, the odd-numbered items may be used for students needing make-up exams. The items are designed to be straight-forward and unambiguous. They are NOT intended to trick the student, but instead to provide an honest evaluation of the student's ability. There are no "curve balls" or "sliders"; instead, the questions all come "right down the middle", and although some may require a very careful reading, the student who is thoughtful and prepared should not find them overly difficult. One of the criticisms of the multiple-choice and true-false formats is that they reward rote memorization rather than true understanding. Although this can certainly at times happen, especially when the items are poorly designed, a carefully prepared multiple-choice test, such as the one presented in this manual, can assess a student’s ability to apply concepts to problem-solving situations. Rather than breaking up the unity of knowledge and isolating the pieces, as critics typically charge, a well- designed multiple-choice test demands that the student be able to understand concepts and bring facts together (Aiken, 1988). One fairly recent report showed that multiple-choice items may actually be more culturally fair than are essay questions. Verbally adept but uninformed students can sometimes bluff their way through essay exams, a tactic that is used less often by minorities (Science Agenda, 1990). Although some poorly prepared students will always insist on calling multiple-choice items, "multiple-guess tests", a careful analysis of student responses allows the instructor to illuminate a student's thought process in rather sharp detail (often to the amazement of the complaining student) . Finally, the manual also includes the answers to all the even numbered text problems (the odd-numbered answers are presented in the text itself). Aiken, L.R. (1988). Psychological testing and assessment (6th ed.). Boston: Allyn and Bacon. Evans,W. A., Krippendorf,M.,Yoon,J.H.,Posluszny,P. & Thomas, S. (2009). Science in the prestige and national tabloid presses. Social Science Quarterly, 71, 105-117. Science Agenda. (1990). New directions in educational testing. Science Agenda. (August-September), 14. iii
CONTENTS TOPIC
PAGE
Introduction:
i-xii
CHAPTER 1: INTRODUCTION TO STATISTICS
1
Suggestions for Class Activities Statistics and the Media Multiple Choice Items True-False
1 3 7
CHAPTER 2: PERCENTAGES, GRAPHS AND MEASURES OF CENTRAL TENDENCY Suggestions for Class Activities The Mean is still the Mean Assessing Central Tendency Your Students as Statistical Consultants Averaging Averages Evaluating Percentages The Mean and Adding a Constant The Mean and Multiplying by a Constant The Mean and Independent Measures Multiple Choice Items True-False Calculate the Values
8
CHAPTER 3: MEASURES OF VARIABILITY Suggestions for Class Activities Quartiles Anyone? How Normal is Normal? Skewing the Distribution Show Your Cash What About Constants? The SD and Multiplying by a Constant Multiple Choice Items True-False Calculate the Values
22 22 22 22 23 23 23 24 25 33 35
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8 8 8 8 9 9 10 11 11 12 20 21
CHAPTER 4: THE NORMAL CURVE AND z SCORES Suggestions for Class Activities Means Z Scores and Skewness Small Samples and Z Scores Remembering Z Scores Multiple Choice Items True-False Calculate the Values
38 38 38 38 39 40 49 51
CHAPTER 5: z SCORES, T SCORES AND OTHER NORMAL CURVE TRANSFORMATIONS Suggestions for Class Activities Curing the Algebra Phobe Translating Into T Scores Using Table 5.1 : Finding Stanines Multiple Choice Items True-False Calculate the Values
54 54 54 55 56 57 65 67
CHAPTER 6: PROBABILITY Suggestions for Class Activities The Lottery and Combinations Low Probabilities and the Impossible Multiple Choice Items True-False Calculate the Values
70 70 70 70 72 79 81
CHAPTER 7: STATISTICS AND PARAMETERS Suggestions for Class Activities Ask Me, and I Will Tell You Multiple Choice Items True-False Calculate the Values
84 84 84 85 93 95
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