A new study will be conducted to determine whether a low fat diet is effective in lowering SBP. Study subjects from the sample will be randomized to the low-fat diet group or to a normal-diet group. The investigators will randomly assign 50% of subjects to the low-fat group and 50% to the normal-diet group. How many total subjects should be studied to have 80% power for detecting a reduction of 10 mmHg in SBP due to exercise, assuming a 0.01 type I error and 2-sided alternative hypothesis? Briefly describe the approach you used.
How do I figure this out?
There are two data sets (which contain demographics (subject.dat) and clinical data (clinic.dat) with the following data descriptions (and are
attached):
Subject.DAT
Variable Columns Description
ID 1-5 Subject ID
Sex 7 ,
Age 9-12 Age in years
Weight 14-22 Weight in kilograms
Height 25-32 Height in meters
Clinic.DAT
Variable Columns Description
ID 1-5 Subject ID
SBP 15-17 Systolic blood pressure (mmHg)
Chol 25-27 Total cholesterol (mg/dl)
HDL 30-32 High density lipids (mg/dl)