
Sample Size Determination for Independent Outcomes 11
size that is too large or too small. The statistical method used for sample size
calculation should be the same as that used for data analysis.
1.3.2 One–Sample Test for Means
We illustrate the sample size calculation using a one–sided test through an
example. Suppose that the total cholesterol levels for male college students are
normally distributed with a mean (µ) of 180 mg/dl and a standard deviation
(σ) of 80 mg/dl. Suppose that an investigator would like to examine whether
the mean total cholesterol level of the physically inactive male college students
is higher than 180 mg/dl using a one–sided ...