Examples: (Z-test for Proportion)

Example1:  An educator estimates that the dropout rate of seniors at high school in Ohio is 15%. Last year, 38 seniors from a random sample of 200 Ohio seniors withdrew. At α=0.05, is there enough evidence to reject the educators claim?

Step1. State the hypotheses and identify the claim.

H0: p = 0.15 (claim)
        H1: p ≠ 0.15

Step2. Find the critical value(s).

Since α=0.05, and the test is two-tailed, the critical values are ±1.96

Step3. Compute the test value.

Step4. Make the decision. 

Do not reject the null hypotheses since that test value falls outside the critical region.

Step5. Summarize the results. 

There is not enough evidence to support the claim that the dropout rate for seniors in high school in Ohio is 15%.

Posted By: Andrea Beatrice Pechueco