Question

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=12.5 based on earlier​ studies? Suppose the doctor would be content with 90% confidence. How does the decrease in confidence affect the sample size​ required?

Answer 1

Explanation:

confidence coefficient for 99% is 2.58

2.58 * 19.4/sqrt(n) = 0.04

2.598*19.4/0.04 = sqrt(n)

( 2.598*19.4/0.04)^2 = n

1587676