Hypothesis Test for Proportions Section 10.3 One Sample

Remember: Properties of Sampling Distribution of Proportions Approximately Normal if

Test Statistic

Conditions  

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)=30 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?

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

If the significance level is not stated – use 0.05.

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

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

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.