PRACTICE PROBLEMS 1 A study is run to estimate the mean tota

PRACTICE PROBLEMS 1. A study is run to estimate the mean total cholesterol level in children 2 to 6 years of age. A sample of nine participants is selected and their total cholesterol levels are measured as follows: 185 225 240 196 175 180 194 147 223 Generate a 95% CI for the true mean total cholesterol levels in children

Solution

Given n=9, xbar=196.11, s=29
a=0.05, |t(0.025, df=n-1=8)|=2.31(check student t table)

So 95% CI is
xbar ± t*s/n

--> 196.11 ± 2.31*29/3

--> (173.78, 218.44)