1. Large Sample Test
for a
Proportion

2. Conditions
• Simple random Sample
• Each sample point has just two possible
outcomes (success and failure)
• Sample includes at least 10 successes and 10
failures
(np>10 and nq>10 )
• Population size is at least 10 times larger than
the sample

3. Conducting a Hypothesis test
1- state the hypothesis: Ho & Ha (mutually exclusive)
2- Analysis Plan
* one sample z-test to determine whether the hypothesized
population proportions differs significantly from the observed sample
proportion
3- Analyze: find the TS and its associated P-value
* SD (σ) of a sampling distribution p= hypothesized value
of population
proportion in null
hypothesis
*TS: z-score: z= (p*- p) p*= sample proportion
σ σ= SD of sample statistic
*P-value- probability of observing a sample statistic as extreme as the TS
(USE appendix A)
4- Interpret- compare the P-value to the significance level and reject null when the
P-value is less than the Significance level

4. Choosing the sample size