stastics
posted by Kim .
I'm having a hard time with question, can someone help me?
A random sample of medical files is used to estimate the proportion p of all people who have blood type B. If you have no preliminary estimate for p, how many medical files should you include in a random sample in order to be 85% sure that the point estimate Final26main will be within a distance of 0.1 from p?
possible answers
208
8
4
104
52

n=p(1p(Zc/E)sqrd
=(.5)(.5)(1.44/.1)sqrd
=51.84
=52