1. Chapter 16
Sections 3-4

2. Bell Ringer
b. Would the following make the interval smaller or larger? Why?

3. I CAN:

4. Daily Agenda
Bell Ringer
Review Bell Ringer
Section 16.3
Section 16.4

6. What does confidence level C mean?

16. The z confidence interval for the mean of a Normal population illustrates several important properties that are shared by all confidence intervals in common use.
The user chooses the confidence level, and the margin of error follows from this choice.
We would like high confidence and also a small margin of error.
High confidence says that our method almost always gives correct answers.
A small margin of error says that we have pinned down the parameter quite precisely.
The factors that influence the margin of error of the z confidence interval are typical of most confidence intervals.

17. How do we get a small margin of error
How do we get a small margin of error? The margin of error for the z confidence interval is:
This expression has z* and σ in the numerator and in the denominator. Therefore, the margin of error gets smaller when:
z* gets smaller
σ is smaller
n gets larger

18. How does level of confidence affect the margin of error?

19. 95% confidence interval when n= 20 (already done above)
How does size affect confidence intervals?

22. YOUR SUMMARY AND NOTES FROM CHAPTER 16