A human papilloma virus (HPV) vaccine was tested in 70 randomly selected adolescent women who were cancer-free from the general population. After 5 years, 28 women had developed cervical cancer and 42 had no evidence of cervical cancer. Let ? equal the population proportion of new cervical cancer cases in adolescent women at 5 years beyond HPV-vaccination.

Analysis of the data

. prtesti 70 28 .5, count One-sample test of proportion x: Number of obs = 70 Variable Mean Std . Err. [95% Conf . Interval] . 058554 . 2852363 . 5147637 p = proportion (x) 2 = -1. 6733 Ho: p = 0.5 Ha: p 0.5 Pr (Z 2 ) = 0.0943 Pr (Z > z) = 0.9529I. The probability that 0.250.50 is 0.05. TF iii. We are 95% confident that the interval (0.25,0.50) includes TI. TF iv. 95% of the time, a randomly chosen sample proportion will be between 0.25 and 0.50. TF