AP STATISTICS: Ms. Jetmore 2015-2016
Syllabus Chapter 8: Estimating with Confidence
Day
T Jan 5
Topic
Hand back Finals, projects, books
Introduce Chapter 8
Assignment
W Jan 6
8.1 The Idea of a Confidence Interval, Interpreting
Confidence Levels and Confidence Intervals
p. 481; 5, 7, 9, 11, 13
read p 476-481
R Jan 7
8.1 Using Confidence Intervals Wisely,
Constructing a Confidence Interval
p. 483; 17, 19-24
read p 484-490
F Jan 8
8.2 Conditions for Estimating p, Constructing a
Confidence Interval for p
p. 496; 27, 31, 33, 35, 37
read p 490-495
M Jan 11
8.2 Putting It All Together: The Four-Step Process,
Choosing the Sample Size
p. 497; 41, 43, 47, 49-52
review 467-495
T Jan 12
FRQuesday
W Jan 13
Review 8.1 and 8.2 – AP Multiple choice questions
Quiz 8.1 and 8.2 (30 points)
read p. 499-510
R Jan 14
8.3 When  is Known: The One-Sample z interval for
a Population Mean, When  is Unknown: The t
Distributions, Constructing a Confidence Interval for 
p. 518; 55, 57, 59, 63
read p 511-517
F Jan 15
8.3 Using t Procedures Wisely
p. 519; 65, 67, 71, 73, 75-78
M Jan 18
No School – Dr. Martin Luther King Jr Day
T Jan 19
FRQuesday
W Jan 20
Chapter 8 Review – part 1
p. 522; Chapter review 1-5
R Jan 21
Chapter 8 Review – part 2
p. 522; Chapter review 6-10
F Jan 22
Chapter 8 Test
Read p. 467-475
Tutoring is available most mornings 7:30-8:00am and after school as needed.
Additional assistance is available at: rhsjetmoremath.pbworks.com
Chapter Objectives
Section 8.1 – Confidence Intervals: The Basics
 Interpret a confidence level.
 Interpret a confidence interval in context.
 Understand that a confidence interval gives a range of plausible values for the parameter.
 Understand why each of the three inference conditions – Random, Normal, and Independent – is
important.
 Explain how practical issues like nonresponse, under coverage, and response bias can affect the
interpretation of a confidence interval.
Section 8.2 – Estimating a Population Proportion
 Construct and interpret a confidence interval for a population proportion.
 Determine critical values for calculating a confidence interval using a table or calculator.
 Carry out the steps in constructing a confidence interval for a population proportion: define the
parameter; check conditions; perform calculations; interpret results in context.
 Determine the sample size required to obtain a level C confidence interval for a population proportion
with a specified margin of error.
 Understand how the margin of error of a confidence interval changes with the sample size and the level
of confidence C.
 Understand why each of the three inference conditions – Random, Normal, and Independent – is
important.
Section 8.3 – Estimating a Population Mean
 Construct and interpret a confidence interval for a population mean.
 Determine the sample size required to obtain a level C confidence interval for a population mean with a
specified margin of error.
 Carry out the steps in constructing a confidence interval for a population mean: define the parameter;
check conditions; perform calculations; interpret results in context.
 Determine sample statistics from a confidence interval.
 Understand why each of the three inference conditions – Random, Normal, and Independent – is
important.
AP Exam Tips
 On a given problem, you may be asked to interpret the confidence interval, the confidence level, or
both. Be sure you understand the difference: the confidence level describes the long-run capture rate
of the method and the confidence interval gives a set of plausible values for the parameter.
 If a free-response question asks you to construct and interpret a confidence interval, you are expected
to do the entire four-step process. That includes clearly defining the parameter and checking
conditions.
 You may use your calculator to compute a confidence interval on the AP exam. But there’s a risk
involved. If you just give the calculator answer with no work, you’ll get either full credit for the “Do” step
(if the interval is correct) or no credit (if it’s wrong). We recommend showing the calculation with the
appropriate formula and then checking with your calculator. If you opt for the calculator-only method,
be sure to name the procedure (e.g., one-proportion z interval) and to give the interval (e.g., 0.514 to
0.606).
Free-Response Questions from Previous AP Exams
Questions can be found on the AP Central Web site:
http://apcentral.collegeboard.com/apc/members/exam/exam_questions/8357.html.
Students should be able to answer all the free-response questions listed with material in this chapter.
Questions that contain content from this chapter but also require content from later chapters are listed in the
last chapter required to complete the entire question. Some of these problems we will do in class as warm-up
problems. You may do the others to help you understand the content from this chapter as well as to prepare
for the AP exam in May.
Year
Question
2000
2000
2
6
2002
2002B
1
4
2003
6
2003B
6
2005
5
2008B
2010
3
3
2010B
4
Content
Conditions for a one-sample t interval for a population mean
One-sample z interval for a population proportion, Combining Normal random
variables, Independence, Anticipating patterns in a scatterplot
Precision of interval estimates, Using confidence intervals to make decisions
One-sample z interval for a population proportion, Interpreting a confidence level,
Using confidence intervals to make decisions
Interpreting a graph, One-sample z interval for a population proportion, Using
confidence intervals to make decisions
One-sample z interval for a population proportion, Interpreting a confidence level,
Determining sample sizes for different subgroups (Cl for a proportion)
Sources of bias in a survey, Determining sample size (Cl for a proportion), Stratified
random sampling
Determining sample size (Cl for a mean), Practical constraints
Interpreting a confidence level, Using confidence intervals to make decisions,
Determining sample size (Cl for a proportion)
One-sample z interval for a population proportion, Effect of sampling without
replacement