1. Hypothesis Test for Proportions
Section 10.3
One Sample

2. Remember: Properties of Sampling Distribution of Proportions
Approximately Normal if

3. Test Statistic

4. Conditions

5. p=true proportion of seniors who dropout
Educators estimate the dropout rate is 15%. Last year 38 seniors from a random sample of 200 seniors withdrew. At a 5% significance level, is there enough evidence to reject the claim?
p=true proportion of seniors who dropout
Assumptions:
(1) SRS
(2) Approximately normal since np=200(.15)= and nq=200(.85)=270
(3) 10(200)=2000 {Pop of seniors is at least 2000}
Therefore the large sample Z-test for proportions may be used.
Fail to reject Ho since p-value >α. There is insufficient evidence to support the claim that the dropout rate is not 15%. What type of error might we be making?

6. PHANTOMS P arameter H ypotheses A ssumptions N ame the test
T est statistic
O btain p-value
M ake decision
S tate conclusions in context

7. If the significance level is not stated – use 0.05.

8. Reject Ho
There is sufficient evidence to support the claim that …..

9. Fail to Reject Ho
There is insufficient evidence to support the claim that ….

10. Experts claim that 10% of murders are committed by women
Experts claim that 10% of murders are committed by women. Is there evidence to reject the claim if in a sample of 67 murders, 10 were committed by women. Use 0.01 significance.