1. A high school counselor wants to examine whether the teenage pregnancy rate at her school is different from the rate nationwide. She knows that the rate nationwide is 15 %. She randomly selects 80 female students from her high school. She finds that 9 out of 80 students are either pregnant now or have been pregnant previously.
a. What statistical test should be used to analyze the data?
b. Identify H0 and Ha for this study
c. Conduct the appropriate analysis
d. Should H0 be rejected? What should the researcher conclude?
a) z test
b) H0: p = 0.15
Ha: p not equal 0.15
c) z = (phat - p)/sqrt(p*(1-p)/N)
z = (9/80 - 0.15)/sqrt(0.15*0.85/80)
z = -0.93933
d)This test statistic is not outside those values.
Therefore, we do not reject the null hypothesis.
The rate at the school is not different from the nationwide rate.