A doctor wants to estimate the mean HDL cholesterol of all 20-29 year old females. How many subjects are needed to estimate the HDL cholesterol within 2 points with 99% confidence assuming s=18.2? based on earlier? studies? Suppose the doctor would be content with 95% confidence. How does the decrease in confidence affect the sample size required?
A 99% confidence level requires ---- subjects (round up to nearest whole number)
A 95% confidence level requires ---- subjects (round up to nearest whole number)