Homework: p.657 # 10.33-10.35
10.3 Estimating a Population Proportion
Reminders of a sampling distribution of :
normal if np and n(1-p) 10
Conditions for inference about a proportion p:
1. SRS
2. Normality
3. Independence
One sample z Confidence Interv
Common Confidence Levels: capturing the central C% of the Normal
sampling distribution
or
Confidence Level
Tail Area
90%
0.05
95%
0.025
99%
0.005
Steps for Constructing a Confidence Interval:
1.
2.
3.
4.
z*
Conditions for Inference about Mean :
1.
2.
3.
O
Ex. 10.5 on page 630: Constructing a confidence interval for the mean video screen
tension. The standard deviation for the tensions readings is . Given the following
tensions readings from an SRS of 20 screens from a single days production, construct
and
2.
spread of t-dist. > z-dist.
more area in tails because using s to estimate
introduces more variation
3.
as df increases, curve approaches N(0, 1)
when sample is large, little variation is caused
One sample t Confidence Interval for a Population Mean (
Paired t procedure: used to compare the responses to the two treatments in a
_
_ _ or _-&-_ observations on the
same subjects,
apply one-sample t procedures to observed _
The parameter in a paired t procedure is:
1.
the population _ _ of 2 treatments of
m
10.1 Confidence Intervals: The Basics
_ _ provides methods for drawing conclusions about a
population from sample data (sampling distributions).
1.
2.
Ex. 10.1 on page 618: A university proposes to use the IQ scores of current students
as a marketing tool
Determining Sample Size: To determine the sample size n that will yield a level C
confidence interval for a population mean with a specified margin of error m, solve for n
for
Read Cautions on page 636
Ex. 10.7 on page 635: Researchers would like to estim
Name_Date_Score_
_/20
Due:_
Chapter 10: Estimating with Confidence
10.1 Confidence Intervals: The Basics (pp.617-642)
1.
In statistics, what is meant by a 95% confidence interval? 95% confidence level?
Sketch and label a 95% confidence interval for the st
10.2 Estimating a Population Mean (pp.642-662)
7.
In general, what is meant by the standard error of a statistic?
What is the standard error of the sample mean ?
8.
How do you calculate the degrees of freedom for a t distribution?
9.
Describe the similari