Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability (.005) and its Z score.
3 = Z (s/√n) = 2.575 (15.8/√n)
Solve for n.
A doctor want to estimate the HDL cholesterol of all 20- to 29- year old females. how many subjects are needed to estimate the HDL cholesterol within 3 points with 99% confindence assuming s=15.8 based on earlier studies?
1 answer
1 answer