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AP Statistics 2005An Apex Learning Guide
By Kaplan Educational Centers
KaplanCopyright © 2005 Kaplan Educational Centers
All right reserved.
Chapter 1: Inside the AP Statistics Exam
Before you plunge into studying for the AP Statistics Exam, let's take a step back and look at the big picture. What's the AP Statistics Exam all about? How can you prepare for it? How's it scored? This chapter and the next will answer these questions and more.
What Is the Advanced Placement (AP) Program®?
Through the Advanced Placement Program, you can take college-level courses while you are in high school. Based on your grade on an AP Exam, colleges and universities can grant you placement or college credit or both.
In addition to getting a head start on your college coursework, you can improve your chances of acceptance to competitive schools since colleges know that AP students are better prepared for the demands of college courses. There's also the money you can save on tuition if you receive credit!
An Overview of the Test Structure
The AP Statistics Exam is administered in May by the College Board's AP Services. The exam is three hours long, so developing your stamina is very important. The exam consists of two equally weighted sections: Section I -- Multiple-Choice, and Section II -- Free-Response.
Section I-- Multiple-Choice
There are 40 multiple-choice questions. Each multiple-choice question is worth 1 point.
Section II -- Free-Response
The second section of the examination consists of five open-ended questions and one investigative task. Each open-ended question is designed to be answered in approximately 12 minutes. The investigative task is longer and is designed to be answered in 30 minutes.
There's a five-minute break between Section I and Section II.
Calculators and Computers
You will not have access to a computer during the AP Statistics Exam. However, standard computer output may be provided as part of the exam, and you will be expected to be able to interpret it.
You will need to bring a graphing calculator with statistical capabilities to the exam. Your calculator's capabilities should include:
- Computation of descriptive statistics, such as the standard deviation, correlation coefficient, and least-squares linear regression equations
- Graphing of scatterplots, boxplots, histograms, and least-squares linear regression lines
It is also useful if your graphing calculator has a spreadsheet-like format for entering data. The TI-83, made by Texas Instruments, is one example of an appropriate calculator for the AP Statistics Exam.
You are not allowed to use a calculator with a QWERTY keypad because it makes it too easy to type text (such as test questions) into the calculator. Visit the AP Statistics website at collegeboard.com/student/testing/ap/about.html for more about the AP Statistics Exam policies.
Topic Outline for AP Statistics
The breakdown of the AP Statistics Exam covers the four main themes outlined below. The chapters of this book which review those content areas are also listed.
1) Exploring Data -- chapters 3, 4, 5
Exploring univariate data: interpreting graphical displays, summarizing and comparing distributions, measuring centers -- median, mean, measuring spread -- range, interquartile range, standard deviation, measuring position -- quartiles, percentiles, standardized scores
Exploring bivariate data: patterns in scatterplots, correlation and linearity, least squares regression line, residual plots, outliers, and influential points, transformations to achieve linearity
Exploring categorical data: frequency tables, including marginal and joint frequencies for two-way tables
2) Planning a Study -- chapter 6
Data collection: census, sample survey, experiment, observational study
Planning and conducting surveys: simple random sampling, conducting a well-designed survey, sampling error, sources of bias
Planning and conducting experiments: confounding, control groups, placebo effects, blinding, treatments, experimental units, randomization, experimental design, replication and generalizability
3) Anticipating Patterns -- chapters 7 and 8
Probability: relative frequency, law of large numbers, rules of probability, conditional probabilities, independence, discrete and continuous random variables, binomial and geometric distributions, mean and standard deviation
Normal distribution: properties, using tables, central limit theorem
Simulations: sampling distributions, sample proportion, sample means, difference between two proportions, difference between two means
4) Statistical Inference -- chapters 9, 10, 11, 12
Confidence intervals: for proportions, for means, for difference between two proportions, for difference between two means
Tests of significance: null and alternative hypotheses, p-values, one-and two-sided tests, large sample tests for proportions, means, difference of proportions, difference of means, chi-square test for goodness of fit and independence
Normally distributed data: t-distribution, single-sample t procedures, two-sample t procedures (independent and matched pairs), inference for slope of least squares lines
How the Exam Is Scored
The AP Statistics Exam is scored on a scale of 1 to 5, with 5 being the highest grade. The scores are defined as follows:
5 Extremely well qualified
4 Well qualified
2 Possibly qualified
1 No recommendation
In 2002, the mean grade of the 49,824 candidates who took the AP Statistics Exam was 2.77. Keep in mind that each college decides for itself which AP scores will be accepted for advanced placement or college credit. Many schools award one semester of placement or credit for a score of 3 or higher on the AP Statistics Exam, but some schools might require a 4 or 5, and there are a few schools that do not award college credit at all.
It would not be correct to say that the AP Exam is graded "on the curve." How other students do on the same exam will not affect your score. However, some multiple-choice questions are used from one year to the next to allow for a calibration of the scores, ensuring that scores reflect the same statistical strength of performance each year. For this reason, the cut-offs for each score level do not stay constant from year to year.
How Are Exams Graded?
The multiple-choice section of the exam is graded by computer. The free-response section is graded by faculty consultants -- college professors and AP teachers who are specially trained to assess the questions. Students' names and schools are concealed on the free-response booklets to ensure fairness in the grading process.
Scoring the Multiple-Choice Questions
For multiple-choice questions, there is a penalty for answering incorrectly, as opposed to simply leaving an item blank. (This is sometimes called a guessing penalty, but it is really a wrong answer penalty. If you guess correctly, you're in great shape!)
Here's how the scoring works: You receive 1 point for a correct answer, 0 points for no answer, and -1/4 point for a wrong answer. For example, getting 30 correct and 10 wrong would give you a score of 30 - (10 x 1/4) = 27.5. We'll talk more about guessing on the AP Statistics multiple-choice section in the next chapter.
Scoring the Free-Response Questions
The free-response questions are graded holistically, meaning that the graders evaluate your answer as a total package rather awarding partial credit for separate parts of your work.
A four-point scale is used (0-4 points possible) on each question. A grader evaluating the quality of your work bases the score on two things:
1) Statistical knowledge: Have you identified the important components of the problem? Have you demonstrated correct statistical concepts and techniques that result in a correct solution?
2) Communication: How well have you explained what you have done and why? Have you clearly stated the conclusions that you have drawn?
How Do I Get My Grade?
AP Grade Reports are sent in July to each student's home, high school, and any colleges designated by the student. Students may designate the colleges they would like to receive their grade on the answer sheet at the time of the test. Students may also contact AP Services to forward their grade to other colleges after the exam, or to cancel or withhold a grade.
AP Grades by Phone
AP Grades by phone are available for $15 a call beginning July 1. A touch-tone phone is needed. The phone number is (888) 308-0013.
Registration and Fees
To register for the AP Statistics Exam, contact your school guidance counselor or AP Coordinator. If your school does not administer the exam, contact AP Services for a listing of schools in your area that do.
The fee for each AP Exam is $82. The College Board offers a $22 credit to qualified students with acute financial need. A portion of the exam fee may be refunded if a student does not take the test. There may be a late fee for late exam orders. Check with AP Services for applicable deadlines.
For more information about the AP Program and/or the AP Statistics Exam, contact your school's AP Coordinator or guidance counselor, or contact AP Services at:
P.O Box 6671
Princeton, NJ 08541-6671
Phone: (609) 771-7300; (877) 274-6474
Fax: (609) 530-0482
The College Board offers a number of publications about the Advanced Placement Program, including: Advanced Placement Program Course Description -- Statistics, A Guide to the Advanced Placement Program, and the AP Bulletin for Students and Parents. You can order these and other publications online at collegeboard.com, or call AP Services for an order form.
Copyright © 2005 by Apex Learning Inc.
Excerpted from AP Statistics 2005 by Kaplan Educational Centers Copyright © 2005 by Kaplan Educational Centers. Excerpted by permission.
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