June 22, 2012 - Quiz Time

       First grading is already over for us III-Gold and we are now facing the 2^nd grading. Last Wednesday, we had taken our first quiz for the 2^nd Grading. It was all about z-test for proportions. Even if it’s only a two-item test, still some of us are confused in stating our hypothesis. But luckily all of us have finished it and most of us get a high score.

But I will give you an example of a problem that is similar to the items of the test that we have taken. And this will also be a sort of review for us.

PROBLEM:

         

 A doctor claims that 26% of the babies born in Africa’s National Hospital are above normal. To see if this claim is valid, the doctor selected 55 samples and found out that 22 are above normal. At alpha= 0.05, test the claim that 26% of the babies are above normal.

Solution:

       Step 1: State the Hypothesis

                   *H₀ : p=0.26 (claim)

                   * H_I : p=0.26

      

      Step 2: Solve for the Critical Value

                 *Alpha=0.04, two-tailed test, C.V= ± 1.96

    

      Step 3: Solve for the z=test value

                Z= p̂-p/ (p)(q)/n

                Z= 0.4-0.26/(0.26)(0.74)/55

                Z= 2.37

      Step 4: Make the decision

                 *Reject the null hypothesis

      Step 5: Summarize the results

                 *There is enough evidence to reject the claim that 26% of the babies born in Africa’s National Hospital are above normal

          I hope that you understand my discussion.

By: Dustin Joshua A. Esquia III- Gold