A random sample of medical files is used to estimate theproportion p of all people who have blood type B.
(a) If you have no preliminary estimate for p, how manymedical files should you include in a random sample in order to be85% sure that the point estimate p̂ will be within adistance of 0.06 from p? (Round your answer up to thenearest whole number.)
medical files
(b) Answer part (a) if you use the preliminary estimate that about13 out of 90 people have blood type B.
medical files
