1. Introduction to Inference
Chapter 10
Introduction to Inference

2. Statistical Inference
Provides methods for drawing conclusions about a population from the sample data

3. Estimating with Confidence
Section 10.1
Estimating with Confidence

4. Confidence Interval
A level C confidence interval for a parameter has 2 parts:
An interval calculated, usually of the form estimate ± margin of error
Confidence level C which gives the probability that the interval will capture the true parameter in repeated samples.

5. Conditions for Constructing
The data comes from an SRS from the population of interest
The sampling distribution of x bar is approximately normal

6. Critical Values
Upper critical value is the number z* with probability p lying to its right under the standard normal curve
You can use Table C to fnd z* for common confidence levels

7. Confidence Interval for a Population Mean
SRS of size n,
unknown  and known 
Formula is given on pg. 546

8. To Construct a Confidence Interval
Identify the population of interest and the parameter to draw conclusions about
Choose the appropriate inference procedure, verify the conditions for using the selected procedure

9. If the conditions are met, CI = estimate ± margin of error
Interpret results in the context of the problem
“We are 95% confident that the true mean of …. is between …”

10. Margin of Error z*(/n)
Gets smaller when z* gets smaller, or  gets smaller or n gets larger
To determine sample size for desired margin of error, m, set up the inequality z*(/n)  m and solve for n

11. Practice Problems
pg. 556 #