1. Chapter 12 Inference for Proportions
AP Statistics
12.1 – Inference for a Population Proportion

3. Conditions for Inference of Step II: (z – procedures)

4. Conditions for Inference of (z – procedures)

5. Cautions for Proportions
Often proportions use surveys . . .
Many different biases can be introduced:
Undercoverage bias
Non-response bias
Lack or Realism bias – lying, uncomfortable
More likely that sample proportions are overestimates or underestimates of the true population proportion.

6. Z – procedures: Step III

10. How about a 95% confidence interval?

11. Choosing the Sample Size

13. Chavez (take 2) What if we only want a 2.5% ME?
Note: Smaller ME’s require larger sample sizes!