One of the best strategies to help students prepare for the AP Statistics Exam is, well, an AP Statistics Exam. One that is real deal College Board and graded using the real deal College Board rubrics.
Making a Plan
Best case scenario, you give students the full 3 hour experience (90 minutes multiple choice, 90 minutes free response). We have done this with students on Friday evening or Saturday morning in the past. This won't work for everyone, so the next best scenario is to use 3 or 4 class periods.
Finding Questions for the Practice Exam
2002, 2007, 2012 are available for purchase from College Board. Also, your College Board Professional account has three full MC exams. Once you have logged in, click "AP Course Audit" then the "Resources" tab on the top, then "Practice Exams and Secure Documents" in the dropdown. Here you will have access to the full 2017, 2018, and 2019 international exams. These international exams are also available as Practice Exams in AP Classroom.
Note: As a fellow AP Stats teacher who uses these exams as an honest assessment of student understanding, please help keep these documents secure by not allowing students to take them out of the room and not posting them on the internet. Like...pretty please.
Every Free Response Question from 1997 and the rubrics are available on the College Board website. There is also sample student responses and scoring statistics. Honestly, I love the College Board for these resources. There are additional Free Response questions in the "Practice Exams and Secure Documents" in your College Board Professional account.
Grading the Practice Exam
All of the rubrics for the free response are provided on the College Board website. Grade the questions as closely as you can to the College Board rubrics. This is valuable feedback to students and also good insight for us as teachers to improve our instruction.
If you prefer to save 12 hours of your life, have the students grade the Free Response. This can be a powerful exercise in helping them to understand the rubrics. Here are some resources for you to use if you give the 2017 Free Response Questions (this link includes a Power Point to use with your students to help them grade their own practice exam)
What Score Do I Put in the Gradebook?
If you are going to put a score in the gradebook, consider the following system for "curving" the scores. A cut score of around 70 is usually needed to get a 5 on the AP Exam, so we map that to a 90 in the gradebook. The cut scores change from year to year, but (70, 57, 44, 33) is usually close. Here is how we make the curve:
Raw AP Exam Score --> Gradebook Score
70 --> 90
57 --> 80
44 --> 70
33 --> 60
In your calculator, put the raw scores in List 1 and the gradebook scores in List 2. Run a cubic regression on the data and store the equation in Y1. Use the equation for each student to calculate their gradebook score.