It is well known that the concentration of cholesterol in blood serum
increases with age, but it is less clear whether cholesterol level is also
associated with body weight. Table 6.18 shows for thirty women serum
cholesterol (millimoles per liter), age (years) and body mass index (weight
divided by height squared, where weight was measured in kilograms and height
in meters). Use multiple regression to test whether serum cholesterol is
associated with body mass index when age is already included in the model.
