As part of a study conducted in France investigating the effectiveness of the drug mifepristone (RU 486) for terminating early pregnancy, 488 women were administered mifepristone followed 48 hours later by the single dose of second drug, misopristol. In 473 of these women, the pregnancy was terminated.
a. Estimate the proportion of successfully terminated early pregnancies among women using the described treatment regimen.
b. Construct a 95% confidence interval for the true population proportion p.
c. Interpret this confidence interval.
d. Calculate a 90% confidence interval for p.
e. How does the 90% confidence interval compare to the 95% interval?