1. Inference for Proportions
Chapter 12

2. Inference for a Population Proportion
Section 12.1

3. Sample Proportion p hat mean = p standard deviation (p(1 – p)/n)
# of successes/# of observations
mean = p
standard deviation (p(1 – p)/n)
If np and n(1 – p)  10, p hat is approximately normal

4. standard error-replace p with p hat Confidence interval
z statistic
standard error-replace p with p hat
Confidence interval
estimate ± z* SEestimate

5. Conditions for Inference About a Proportion
Data are an SRS from population on interest
Population at least 10 times as large as sample
For test H0: p = p0 sample size n so large that both np0 and n(1 – p0) are 10 or more

6. Formulas for z procedures
Formula for samples size for desired margin of error
p.695

7. Practice Problems
pg. 698 # , 12.21