A doctor wants to estimate the mean HDL cholesterol of all? 20- to? 29-year-old females. How many subjects are needed to estimate the mean HDL cholesterol within 3 points with 99 % confidence assuming s=14.5 based on earlier? studies? Suppose the doctor would be content with 90 %confidence. How does the decrease in confidence affect the sample size? required?
A? 99% confidence level requires _______ subjects ? ?(Round up to the nearest? subject.)