Question

Recent Gallup Poll estimates that 88% Americans believe that cloning humans is morally unacceptable. Results are based on telephone interviews with a randomly selected national sample of n = 1000 adults, aged 18 and older, conducted May 2-4, 2004.

i. Find 95% condence interval for the true proportion? Does 0.9 fall in the interval?
ii. Pretend that you want to replicate Gallup's inquiry in the Atlanta area. What
sample size is needed so that the length of a 95% condence interval for the
unknown proportion of people in the area who believe that cloning humans is
morally unacceptable does not exceed 0.02?
iii. How would you change the sample size if you are sure that the true proportion
exceeds 0.7?

Answer 1